One-to-many air conditioners

Abstract

The present application proposes a one-to-many air conditioner, comprising a compressor, an outdoor heat exchanger, a first valve unit, an indoor unit, a second valve unit and a temperature sensor for detecting coil temperature, subcooling zone temperature and superheating zone temperature. When the one-to-many air conditioner operates in heating mode, after some indoor heat exchangers are in shutdown or standby state for a period of time, enthalpy difference ratio calculations and refrigerant average density calculations of the subcooling zone, superheating zone and two-phase zone are performed based on the superheating zone temperature, subcooling zone temperature and coil temperature. The enthalpy difference ratio is used to define the volume ratio of the subcooling zone, superheating zone and two-phase zone in the indoor heat exchanger; the required total volume of the indoor heat exchanger is calculated through a first logical operation according to the total refrigerant amount, the distribution ratio coefficient of the refrigerant in the indoor heat exchanger under heating conditions, the volume ratio and the average density of the refrigerant; an opening combination calculation is performed according to the total volume of the indoor heat exchanger, the volume of each indoor heat exchanger and the switch status, and the expansion valve opening is adjusted according to the opening combination.

Description

Technical Field

[0001] The present invention relates to the technical field of household appliances, and in particular to a one-to-many air conditioner. Background Art

[0002] One-to-many air conditioners can operate with one outdoor unit and multiple indoor units. Figure 1 Each indoor unit corresponds to an electronic expansion valve. When a one-to-many air conditioner is running in heating mode, in order to ensure the system pressure, the electronic expansion valve corresponding to the indoor unit still needs to be opened to a certain degree even when the indoor unit is not turned on. However, this setting will cause heat leakage, resulting in loss of heating capacity and an increase in the temperature of the room where the indoor unit is located, affecting indoor comfort and reducing the user's body comfort experience.

[0003] In view of this, this application is filed. Summary of the Invention

[0004] The present application provides a one-to-many air conditioner, which calculates the required total volume of the indoor heat exchanger based on the coil temperature, superheat zone temperature and supercooling zone temperature of the indoor heat exchanger, combined with the total refrigerant amount of the refrigerant circulation loop and the distribution ratio coefficient of the refrigerant in the indoor heat exchanger under heating conditions, and then obtains the opening combination of each expansion valve according to the volume and switch status of each indoor heat exchanger, and thereby controls the expansion valve corresponding to the indoor heat exchanger in the shutdown or standby state to realize dynamic valve adjustment, which can effectively solve the heat leakage problem of the indoor heat exchanger in the non-startup state, thereby improving the indoor heating comfort.

[0005] To this end, the present application aims to provide a one-to-many air conditioner, comprising:

[0006] A plurality of indoor units arranged in parallel, each including an indoor heat exchanger;

[0007] an outdoor unit comprising a compressor connected in series with the indoor heat exchanger and an outdoor heat exchanger;

[0008] a first valve unit connected between the indoor heat exchanger and the outdoor heat exchanger and comprising a plurality of first expansion valves arranged in parallel;

[0009] a second valve unit connected between the compressor and the indoor heat exchanger and comprising a plurality of second expansion valves arranged in parallel, wherein the second expansion valves, the first expansion valves and the indoor heat exchangers correspond one to one to control the flow of refrigerant flowing through the indoor heat exchanger;

[0010] A first temperature sensor is provided on the indoor heat exchanger and is used to detect the coil temperature of the indoor heat exchanger;

[0011] A second temperature sensor is provided on a side of the first expansion valve close to the indoor heat exchanger, and is used to detect the temperature of the subcooling zone of the indoor heat exchanger under heating conditions;

[0012] A third temperature sensor is provided on the side of the second expansion valve close to the indoor heat exchanger, and is used to detect the temperature of the superheat zone of the indoor heat exchanger under heating conditions;

[0013] The controller is configured to: when the one-to-many air conditioner operates in heating mode, after some indoor heat exchangers are in a shutdown or standby state for a period of time, perform an enthalpy difference ratio calculation of the subcooling zone, superheating zone, and two-phase zone, and an average refrigerant density calculation based on the superheating zone temperature, the subcooling zone temperature, and the coil temperature; the enthalpy difference ratio is used to define the volume ratio of the subcooling zone, the superheating zone, and the two-phase zone in the indoor heat exchanger;

[0014] The required total volume of the indoor heat exchanger is calculated by a first logical operation based on the total amount of refrigerant, the distribution ratio coefficient of the refrigerant in the indoor heat exchanger under heating conditions, the volume ratio, and the average density of the refrigerant;

[0015] An opening combination calculation is performed based on the total volume of the indoor heat exchangers, the volume of each indoor heat exchanger, and the switch status. The opening size of the first expansion valve and / or second expansion valve corresponding to the indoor heat exchanger in the shutdown or standby state is adjusted according to the opening combination to adjust the heat leakage of the indoor unit.

[0016] In some embodiments of the present application, the first logical operation is: obtaining the total refrigerant average density of the one-to-many air conditioner based on the calculated volume proportions of the subcooling zone, the superheating zone, and the two-phase zone in the indoor heat exchanger and the average refrigerant density;

[0017] The required total volume of the indoor heat exchanger is calculated based on the average density of the total refrigerant, the total refrigerant volume, and the distribution ratio coefficient of the refrigerant in the indoor heat exchanger under heating conditions.

[0018] In some embodiments of the present application, in the enthalpy difference ratio calculation:

[0019] Determine the corresponding saturation pressure according to the superheated zone temperature, subcooled zone temperature and coil temperature;

[0020] According to the superheating zone temperature, coil temperature, subcooling zone temperature and the corresponding saturation pressure, the enthalpy calculation logic is used to obtain the enthalpy values ​​of the inlet and outlet of the superheating zone, the enthalpy values ​​of the inlet and outlet of the two-phase zone, and the enthalpy values ​​of the inlet and outlet of the subcooling zone. Based on this, the enthalpy difference of the inlet and outlet of each zone is calculated to obtain the enthalpy difference ratio of each zone.

[0021] In some embodiments of the present application, the average refrigerant density in the superheated region, the two-phase region, and the supercooled region is calculated using the average refrigerant density calculation;

[0022] In the calculation of the average refrigerant density, the average refrigerant density of the corresponding area is calculated based on the enthalpy values ​​of the inlet and outlet of the corresponding area.

[0023] In some embodiments of the present application, a fourth temperature sensor is further included, which is provided on the outdoor unit and is used to detect the outdoor ambient temperature;

[0024] The controller is configured to: during the operation of the one-to-many air conditioner in the heating mode, when the switch state of the indoor heat exchanger changes, perform an initial valve opening calculation based on the outdoor ambient temperature and the compressor frequency, adjust the opening of the first expansion valve and / or the second expansion valve corresponding to the indoor heat exchanger in the shutdown state or the standby state based on the calculated initial valve opening, and maintain the opening for a period of time before adjusting the expansion valve opening.

[0025] In some embodiments of the present application, the initial valve opening is also related to the number of indoor heat exchangers that are turned on and the heating capacity of the one-to-many air conditioners.

[0026] In some embodiments of the present application, after adjusting the first expansion valve and / or the second expansion valve, the actual subcooling degree at that time is calculated, and based on the actual subcooling degree, the average subcooling degree of each indoor heat exchanger after startup is calculated;

[0027] When the average subcooling degree is not within the target subcooling degree range, the opening of the first expansion valve and / or the second expansion valve is adjusted again to adjust the amount of refrigerant flowing through the indoor heat exchanger per unit time.

[0028] In some embodiments of the present application, a fifth temperature sensor is further included, which is provided on the indoor heat exchanger and is used to detect the temperature of the liquid pipe;

[0029] The controller is configured to obtain an actual subcooling degree of the corresponding indoor heat exchanger according to the maximum coil temperature and liquid pipe temperature in each indoor heat exchanger under heating conditions.

[0030] In some embodiments of the present application, when the first expansion valve or the second expansion valve corresponding to the indoor heat exchanger that is in the shutdown or standby state is operating with an initial valve opening, when the operating frequency change of the compressor is greater than the set change condition, the initial valve opening is recalculated.

[0031] In some embodiments of the present application, the first expansion valve includes a stepper motor and a slider. The controller controls the operation of the stepper motor according to a preset program. The motor rotor of the stepper motor directly drives the slider to move, thereby changing the refrigerant flow rate passing through the first expansion valve.

[0032] During the process of adjusting the opening of the first expansion valve, the adjustment is performed with a set number of steps each time.

[0033] In the above embodiment, the one-to-many air conditioner proposed in the present application includes a compressor, a four-way valve, an outdoor heat exchanger, a first valve unit, an indoor unit and a second valve unit connected in series in sequence, the first valve unit includes a plurality of first electronic expansion valves in parallel, the indoor unit includes a plurality of indoor heat exchangers in parallel, the second valve unit includes a plurality of second electronic expansion valves in parallel, the second expansion valve, the first expansion valve and the indoor heat exchanger correspond one to one to control the refrigerant flow through the indoor heat exchanger, and also includes a first temperature sensor for detecting the coil temperature, a second temperature sensor for detecting the temperature of the supercooling zone and a third temperature sensor for detecting the temperature of the superheating zone. The controller is configured as follows: when the one-to-many air conditioner is operating in heating mode, when some indoor heat exchangers are in shutdown Or after a period of time in the standby state, the enthalpy difference ratio calculation of the supercooling zone, superheating zone and two-phase zone and the refrigerant average density calculation are performed based on the superheating zone temperature, the supercooling zone temperature and the coil temperature. The enthalpy difference ratio is used to define the volume ratio of the supercooling zone, the superheating zone and the two-phase zone in the indoor heat exchanger; the required total volume of the indoor heat exchanger is calculated through the first logical operation according to the total refrigerant amount, the distribution ratio coefficient of the refrigerant in the indoor heat exchanger under heating conditions, the volume ratio and the average density of the refrigerant; the opening combination calculation is performed according to the total volume of the indoor heat exchanger, the volume of each indoor heat exchanger and the switch status, and the opening size of the first expansion valve and / or the second expansion valve corresponding to the indoor heat exchanger in the shutdown or standby state is adjusted according to the opening combination to adjust the heat leakage of the indoor unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 This is a structural diagram of a one-to-many air conditioner in the related art;

[0036] Figure 2 This is a structural diagram of a one-to-many air conditioner provided by the present application according to an exemplary embodiment;

[0037] Figure 3 This is a hardware configuration block diagram of a one-to-many air conditioner proposed in accordance with an exemplary embodiment of the present application;

[0038] Figure 4 Schematic diagram of the structure of the superheating zone, the two-phase zone and the supercooling zone according to an exemplary embodiment of the present application;

[0039] Figure 5 This is a schematic diagram of the interaction between a controller and a terminal device of a one-to-many air conditioner according to an exemplary embodiment of the present application;

[0040] Figure 6 The present application provides a control logic for a one-to-many air conditioner according to an exemplary embodiment;

[0041] Figure 7 The present application provides control logic for enthalpy difference ratio calculation according to an exemplary embodiment;

[0042] Figure 8 For the present application, according to an exemplary embodiment, a control logic for adjusting the opening of the expansion valve according to the degree of supercooling is provided;

[0043] Figure 9 This application provides a control logic for a one-to-many air conditioner with four indoor units according to an exemplary embodiment;

[0044] Figure 10 This is the control logic for first making the expansion valve of the indoor unit in the on state operate at the initial valve opening before adjusting the expansion valve opening according to the exemplary embodiment of the present application;

[0045] Figure 11 This is a schematic structural diagram of a controller provided according to an exemplary embodiment of the present application;

[0046] Figure 12 This is another structural schematic diagram of a one-to-many air conditioner provided by the present application according to an exemplary embodiment;

[0047] In the above figures:

[0048] One-to-many air conditioner 100; indoor unit 1; outdoor unit 2; throttling device 3; compressor 4; four-way valve 5;

[0049] First valve unit 6; second valve unit 7; first expansion valve 61; second expansion valve 71; controller 8;

[0050] First temperature sensor 91; second temperature sensor 92; third temperature sensor 93;

[0051] Fourth temperature sensor 94; fifth temperature sensor 95; bus 81; memory 82;

[0052] Processor 83; communication interface 84; indoor heat exchanger 11; outdoor heat exchanger 21;

[0053] Stop valve 101; filter 111; superheating zone 12; two-phase zone 13; supercooling zone 14; terminal equipment 103. DETAILED DESCRIPTION

[0054] The present invention is described in detail below by way of exemplary embodiments, but it should be understood that elements, structures, and features of one embodiment may be beneficially combined in other embodiments without further description.

[0055] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0056] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0057] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections via an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0058] Figure 2 This is a structural diagram of a one-to-many air conditioner 100 provided in accordance with an exemplary embodiment of the present application. Figure 2 The one-to-many air conditioner 100 shown includes an indoor unit 1, an outdoor unit 2 and a throttling device 3.

[0059] The indoor unit 1 includes multiple indoor heat exchangers 11 in parallel, and the outdoor unit 2 includes a compressor 4, a four-way valve 5, and an outdoor heat exchanger 21 connected in series with the indoor heat exchangers 11. The throttling device 3 includes a first valve assembly 6 and a second valve assembly 7. The compressor 4, the four-way valve 5, the outdoor heat exchanger 21, the first valve assembly 6, the indoor heat exchanger 11, and the second valve assembly 7 form a refrigerant circulation loop.

[0060] There is a pipeline connection between the outdoor heat exchanger 21 and the multiple indoor heat exchangers 11. The pipeline connecting the outdoor heat exchanger 21 and the multiple indoor heat exchangers 11 includes: an air pipe for transmitting gaseous refrigerant and a liquid pipe for transmitting liquid refrigerant.

[0061] The first valve assembly 6 is connected between the indoor heat exchanger 11 and the outdoor heat exchanger 21 and includes a plurality of parallel first expansion valves 61. The second valve assembly 7 is connected between the compressor 4 and the indoor heat exchanger 11 and includes a plurality of parallel second expansion valves 71. The first expansion valves 61, the second expansion valves 71, and the indoor units 1 correspond one-to-one and form a refrigerant branch circuit.

[0062] The indoor heat exchanger 11 has a first inlet and outlet for circulating liquid refrigerant between the first expansion valve 61 and a second inlet and outlet for circulating gaseous refrigerant between the second expansion valve 71. The indoor heat exchanger 11 exchanges heat between the refrigerant flowing through the heat transfer pipe connecting the first and second inlets and outlets and the indoor air. The compressor 4 compresses low-temperature, low-pressure refrigerant gas into high-temperature, high-pressure refrigerant gas, which is then discharged to the condenser. Compressor 4 is a variable-capacity inverter compressor 4 that can reverse and control the speed of the inverter.

[0063] The outdoor heat exchanger 21 has a third inlet and outlet for circulating the refrigerant between the indoor heat exchanger 11 and the suction port of the compressor 4, and a fourth inlet and outlet for circulating the refrigerant between the outdoor heat exchanger 21 and the first valve unit 6. The outdoor heat exchanger 21 exchanges heat between the refrigerant flowing in the heat transfer pipe connected between the third inlet and outlet and the fourth inlet and outlet and the outdoor air.

[0064] In the heating cycle, the indoor heat exchanger 11 operates as a condenser and the outdoor heat exchanger 21 operates as an evaporator. In the cooling cycle, the indoor heat exchanger 11 operates as an evaporator and the outdoor heat exchanger 21 operates as a condenser.

[0065] In some embodiments, the compressor 4 is used to compress low-temperature, low-pressure refrigerant gas into high-temperature, high-pressure refrigerant gas and discharge it to the condenser. The compressor 4 may be a variable capacity inverter compressor 4 that performs inverter-based speed control.

[0066] The four ports of the four-way valve 5 are respectively connected to the air outlet of the compressor 4, the air intake of the compressor 4, the outdoor heat exchanger 21 and the second valve unit 7. The four-way valve 5 is used to realize the mutual conversion between cooling and heating by changing the flow direction of the refrigerant in the system flow path.

[0067] The outdoor unit 2 further includes an outdoor fan, which generates an airflow of outdoor air passing through the outdoor heat exchanger 21 to promote heat exchange between the refrigerant flowing in the heat transfer pipe between the third inlet and the fourth inlet and the outdoor air.

[0068] The expansion valve expands and reduces the pressure of the refrigerant flowing through it, thus regulating the refrigerant supply within the pipeline. If the expansion valve is opened less, the flow resistance of the refrigerant through it increases. If the expansion valve is opened more, the flow resistance of the refrigerant through it decreases. Thus, even if the states of other components in the refrigerant circulation circuit remain unchanged, the flow rate of refrigerant to the indoor heat exchanger 11 will also change when the expansion valve opening changes.

[0069] In some implementations of this embodiment, the expansion valve may be an electronic expansion valve, which uses an electrical signal generated by an adjusted parameter to control the voltage or current applied to the expansion valve, thereby achieving the purpose of regulating the liquid supply.

[0070] In some implementations of this embodiment, the first expansion valve 61 includes a stepper motor and a slider. The controller 8 controls the operation of the stepper motor according to a preset program. The motor rotor of the stepper motor directly drives the slider to move, thereby changing the refrigerant flow rate passing through the first expansion valve 61.

[0071] During the process of adjusting the opening degree of the first expansion valve 61 , the opening degree is adjusted by a set number of steps each time.

[0072] Similarly, the second expansion valve 71 may also include a stepper motor and a slider. The controller 8 controls the operation of the stepper motor according to a preset program. The motor rotor of the stepper motor directly drives the slider to move, thereby changing the refrigerant flow rate passing through the second expansion valve 71.

[0073] During the process of adjusting the opening degree of the second expansion valve 71 , the adjustment is performed in a set number of steps each time.

[0074] Reference Figure 2 The figure uses four indoor units 1 as an example, and is equipped with electronic expansion valves A, B, C, D, A', B', C', and D'. Electronic expansion valves A and A' are located in the same refrigerant branch, electronic expansion valves B and B' are located in the same refrigerant branch, electronic expansion valves C and C' are located in the same refrigerant branch, and electronic expansion valves D and D' are located in the same refrigerant branch. Each electronic expansion valve can independently control the flow of each refrigerant branch and the opening degree of the electronic expansion valve. Based on the calculation results, the refrigerant flow and the amount of stored refrigerant in the indoor units 1 that are not powered on are intelligently controlled.

[0075] The indoor unit 1 is an indoor hanging unit, for example, and the indoor hanging unit is usually installed on an indoor wall, etc. For another example, an indoor cabinet unit is also a form of the indoor unit 1.

[0076] In some implementations of this embodiment, in the refrigerant circulation loop of the one-to-many air conditioner 100, the refrigerant circulates in a loop consisting of the compressor 4, the condenser, the evaporator, and the expansion valve. Taking the one-to-many air conditioner 100 operating in heating mode as an example, the refrigerant circulation process in the one-to-many air conditioner 100 includes: the compressor 4 draws the low-temperature, low-pressure gaseous refrigerant evaporated by the evaporator into the compressor 4 chamber, compresses it into a high-temperature, high-pressure gaseous refrigerant, and then passes through the second expansion valve 71 into the condenser. The high-temperature, high-pressure gaseous refrigerant is condensed into a high-temperature, high-pressure liquid refrigerant in the condenser. After that, it passes through the first expansion valve 61 and becomes a low-temperature, low-pressure liquid refrigerant. After evaporation in the evaporator, it finally returns to the compressor 4, thereby completing the entire heating cycle.

[0077] In heating mode, the outdoor heat exchanger 21 functions as an evaporator, and the indoor heat exchanger 11 functions as a condenser. In cooling mode, the outdoor heat exchanger 21 functions as a condenser, and the indoor heat exchanger 11 functions as an evaporator. This embodiment is primarily designed for the heating mode of a multi-unit air conditioner 100.

[0078] Reference Figure 12 The air conditioning system of the multi-use air conditioner 100 may further include a shutoff valve 101 and a filter 111. Specifically, each expansion valve is provided with a shutoff valve 101. The first expansion valve 61 is provided with a two-way shutoff valve 101, and the second expansion valve 71 is provided with a three-way shutoff valve 101. The shutoff valve 101 can be used to open or close the corresponding refrigerant branch.

[0079] Two filters 111 are provided, one between the first expansion valve 61 and the outdoor heat exchanger 21, and the other between the second expansion valve 71 and the four-way valve 5. By providing the filters 111, impurities in the refrigerant can be filtered to avoid clogging of the expansion valve.

[0080] Figure 3 This is a hardware configuration block diagram of a one-to-many air conditioner 100 proposed in accordance with an exemplary embodiment of the present application. Figure 3 The one-to-many air conditioner 100 further includes one or more of the following: multiple first temperature sensors 91, multiple second temperature sensors 92, multiple third temperature sensors 93, a fourth temperature sensor 94, a fifth temperature sensor 95, and a controller 8. In addition, the multiple indoor units 1, the outdoor units 2, the compressor 4, the multiple first temperature sensors 91, the multiple second temperature sensors 92, the multiple third temperature sensors 93, the fourth temperature sensor 94, and the fifth temperature sensor 95 are all in communication with the controller 8.

[0081] In some implementations of this embodiment, for any one of the multiple first temperature sensors 91, the first temperature sensor 91 can be set on the indoor heat exchanger 11 to detect the coil temperature of the indoor heat exchanger 11 and send the detected coil temperature to the controller 8.

[0082] In some embodiments, a first temperature sensor 91 may be provided on the coil of each indoor heat exchanger 11 , and the plurality of first temperature sensors 91 may send the temperature values ​​of the coils detected by themselves to the controller 8 .

[0083] In some implementations of this embodiment, for any second temperature sensor 92 among the multiple second temperature sensors 92, the second temperature sensor 92 can be arranged on the side of the first expansion valve 61 close to the indoor heat exchanger 11, for detecting the temperature of the subcooling zone 14 of the indoor heat exchanger 11 under heating conditions, and sending the detected subcooling zone 14 temperature to the controller 8.

[0084] In some embodiments, a second temperature sensor 92 may be provided on a side of each first expansion valve 61 close to the indoor heat exchanger 11 , and the plurality of second temperature sensors 92 may send the detected temperature of the supercooling zone 14 to the controller 8 .

[0085] In some embodiments of this embodiment, for any one of the multiple third temperature sensors 93, the third temperature sensor 93 can be arranged on the side of the second expansion valve 71 close to the indoor heat exchanger 11, for detecting the temperature of the superheat zone 12 of the indoor heat exchanger 11 under heating conditions, and sending the detected superheat zone 12 temperature to the controller 8.

[0086] In some embodiments, a third temperature sensor 93 may be provided on a side of each second expansion valve 71 close to the indoor heat exchanger 11 , and the plurality of third temperature sensors 93 may send the detected temperature of the superheated zone 12 to the controller 8 .

[0087] It should be noted that under the design working conditions, the refrigerant enters the condenser in the state of superheated steam, and gradually turns into a mixture of gas and liquid after heat exchange and cooling, and then leaves the condenser after further heat exchange to supercooled liquid. When the working conditions change, the state of the condenser outlet and the heat exchange capacity of the condenser will change accordingly. According to the possible existence state of the refrigerant in the condenser, the condenser is divided into three phase zones: superheat zone 12, two-phase zone 13 and supercooling zone 14. The division diagram is shown in Figure 1. Figure 4 .

[0088] Taking into account factors such as changes in physical properties with temperature, each phase region can be divided into multiple unit segments. The heat exchange of the refrigerant in the superheated region 12 and the subcooled region 14 is manifested in the change in the refrigerant temperature. The superheated region 12 and the subcooled region 14 can be divided into multiple unit segments according to the refrigerant temperature. The refrigerant exists in a vapor-liquid mixed state in the two-phase region 13, and heat is exchanged through phase change. The temperature of the refrigerant is maintained constant. The heat exchange of the fluid is manifested in the change in the refrigerant enthalpy value. The two-phase region 13 can be divided into multiple unit segments with constant enthalpy values ​​(or constant dryness).

[0089] The fourth temperature sensor 94 is connected to the controller 8 . The fourth temperature sensor 94 is provided on the outdoor unit 2 and is used to detect the outdoor ambient temperature and send the result to the controller 8 .

[0090] The fifth temperature sensor 95 is provided on the indoor heat exchanger 11 and is used to detect the liquid pipe temperature of the indoor unit 1 . The fifth temperature sensor 95 is used to detect the liquid pipe temperature and send it to the controller 8 .

[0091] Those skilled in the art will understand that Figure 3 The hardware structure shown in the figure does not constitute a limitation on the one-to-many air conditioner 100. The one-to-many air conditioner 100 may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0092] In some implementations of this embodiment, the controller 8 can be used to operate the compressor 4, the first expansion valve 61, and the second expansion valve 71, so that the one-to-many air conditioner 100 can operate to achieve various predetermined functions of the one-to-many air conditioner 100.

[0093] In some implementations of this embodiment, the controller 8 may obtain the operating frequency and the operating current value of the compressor 4 at each moment.

[0094] In the embodiment shown in the present application, the controller 8 refers to a device that can generate an operation control signal based on an instruction operation code and a timing signal to instruct the one-to-many air conditioner 100 to execute the control instruction.

[0095] The embodiment of the present application also provides a hardware structure diagram of a controller 8, such as Figure 11 As shown, the controller 8 includes a processor 83 and, optionally, a memory 82 and a communication interface 84 connected to the processor 83. The processor 83, the memory 82 and the communication interface 84 are connected via a bus 81.

[0096] The processor 83 may be a central processing unit (CPU), a general-purpose processor (GP), a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof. The processor 83 may also be any other device having a processing function, such as a circuit, a device, or a software module. The processor 83 may also include multiple CPUs, and the processor 83 may be a single-CPU processor or a multi-CPU processor. The processor 83 herein may refer to one or more devices, circuits, or processing cores for processing data (e.g., computer program instructions).

[0097] The memory 82 can be a read-only memory 82 (ROM) or other types of static storage devices that can store static information and instructions, a random access memory 82 (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory 82 (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer. The embodiment of the present application does not impose any restrictions on this. The memory 82 can exist independently or be integrated with the processor 83. Among them, the memory 82 can contain computer program code. The processor 83 is used to execute the computer program code stored in the memory 82, thereby realizing the control method of the multi-split air conditioning system provided in the embodiment of the present application.

[0098] The communication interface 84 can be used to communicate with other devices or communication networks (such as Ethernet, radio access network (RAN), wireless local area network (WLAN), etc.). The communication interface 84 can be a module, a circuit, a transceiver or any device that can achieve communication.

[0099] The bus 81 may be a peripheral component interconnect (PCI) bus 81 or an extended industry standard architecture (ELSA) bus 81. The bus 81 may be divided into an address bus 81, a data bus 81, a control bus 81, etc. For ease of representation, Figure 11 Only one thick line is used in the figure, but it does not mean that there is only one bus 81 or one type of bus 81.

[0100] In some implementations of this embodiment, the multi-use air conditioner 100 is further provided with a remote controller that communicates with the controller 8 using, for example, infrared or other communication methods. The remote controller allows the user to perform various controls on the multi-use air conditioner 100 and enables interaction between the user and the multi-use air conditioner 100.

[0101] In some embodiments, the multi-use air conditioner 100 further includes a communicator connected to the controller 8 for establishing communication with other network entities. For example, an RF module can be used to receive and transmit signals. Specifically, the RF module can transmit received information to the controller 8 for processing and transmit signals generated by the controller 8. Typically, the RF circuitry may include, but is not limited to, an antenna, at least one amplifier, a transceiver, a coupler, a low-noise amplifier (LNA), a duplexer, and the like.

[0102] For example, the one-to-many air conditioner 100 can receive the control instructions sent by the terminal device 103 through the communicator, and perform corresponding processing according to the control instructions to realize the interaction between the user and the one-to-many air conditioner 100.

[0103] Figure 5 This is a schematic diagram of the interaction between the controller 8 and the terminal device 103 of a one-to-many air conditioner 100 according to an exemplary embodiment of the present application.

[0104] like Figure 5As shown, the terminal device 103 can establish a communication connection with the controller 8 of the air-conditioning system. Exemplarily, any known network communication protocol can be used to establish the communication connection. The above-mentioned network communication protocol can be various wired or wireless communication protocols, such as Ethernet, universal serial bus 81 (USB), FireWire (FIREWIRE), any cellular network communication protocol (such as 3G / 4G / 5G), Bluetooth, wireless fidelity (wireless fidelity, Wi-Fi), NFC or any other suitable communication protocol. The above-mentioned communication connection can be a Bluetooth connection, NFC, Zigbee, wireless fidelity (wireless fidelity, Wi-Fi), etc. The embodiment of the present application does not impose specific restrictions on this.

[0105] It should be noted that Figure 5 The terminal device 103 shown is only an example of the terminal device 103. The terminal device 103300 in this application can be a remote control, a mobile phone, a tablet computer, a personal computer (PC), a personal digital assistant (PDA), a smart watch, a netbook, a wearable electronic device, an augmented reality (AR) device, a virtual reality (VR) device, a robot, etc. This application does not impose any special restrictions on the specific form of the terminal device 103.

[0106] In the heating mode, some indoor units 1 are working and some are in shutdown or standby state. At this time, in order to ensure the pressure in the refrigerant circulation loop, even if the indoor unit 1 is not in the power-on state, the electronic expansion valve corresponding to the indoor unit 1 still needs to be opened to a certain degree, which causes heat leakage.

[0107] To solve the heat leakage problem caused by this operation, refer to Figure 6 .

[0108] In some implementations of this embodiment, the controller 8 is configured to:

[0109] When the one-to-many air conditioner 100 operates in heating mode, it is determined whether some indoor heat exchangers 11 have been in shutdown or standby mode for a preset time (step S61);

[0110] If the preset time is reached in step S61, step S62 is executed to perform enthalpy difference ratio calculation and refrigerant average density calculation of the supercooling zone 14, superheating zone 12 and two-phase zone 13 based on the detected superheating zone 12 temperature, supercooling zone 14 temperature and coil temperature.

[0111] It should be noted that the enthalpy difference ratio is used to define the volume ratio of the subcooling zone, the superheating zone 12 and the two-phase zone 13 in the indoor heat exchanger 11 .

[0112] Then, step S63 is executed to calculate the required total volume of the indoor heat exchanger 11 through a first logical operation based on the total amount of refrigerant in the refrigerant flow path, the distribution ratio coefficient of the refrigerant in the indoor heat exchanger 11 under heating conditions, the calculated volume ratio, and the average density of the refrigerant.

[0113] In step S64 , an opening combination calculation is performed based on the total volume of the indoor heat exchangers 11 , the volume value of each indoor heat exchanger 11 , and the on / off status of each indoor heat exchanger 11 .

[0114] Finally, step S65 is executed to adjust the opening of the first expansion valve 61 and / or the second expansion valve 71 corresponding to the indoor heat exchanger 11 in the shutdown or standby state according to the opening combination to adjust the heat leakage of the indoor unit 1.

[0115] If the preset time is not reached in S61, then continue to execute step S61.

[0116] It should be noted that the opening combination includes the switch status and opening degree of each first expansion valve 61 and each second expansion valve 71 .

[0117] It should be noted that heat leakage refers to the increased power consumption of the one-to-many air conditioner 100 on the basis of the original demand to meet the user's set requirements when the indoor unit 1 is in the non-started state in order to prevent the first expansion valve 61 or the second expansion valve 71 connected to it from being in the closed state due to the system pressure in the heating mode, or the heat exchange amount of the indoor unit in the non-started state.

[0118] Through the above settings, by calculating the required volume of the condenser and adjusting the opening of the expansion valve, the heat leakage of the one-to-many air conditioner 100 in the heating mode is reduced while balancing the system pressure.

[0119] Compared with the one-to-many air conditioner 100 in the related art, the one-to-many air conditioner 100 in the present application changes each refrigerant branch from a single electronic expansion valve to a dual electronic expansion valve system, and can intelligently switch the first expansion valve 61 and the second expansion valve 71 corresponding to the indoor heat exchanger 11 in the off state according to the opening combination, thereby reducing the number of expansion valves opened in the indoor unit 1 in the off state, reducing the heat leakage of the one-to-many air conditioner 100, and improving the heating comfort of the one-to-many air conditioner 100.

[0120] In some implementations of this embodiment, reference Figure 7In the enthalpy difference ratio calculation, the corresponding saturation pressure is first determined according to the temperature of the superheated zone 12, the temperature of the subcooled zone 14 and the coil temperature (step S71); then, according to the temperature of the superheated zone 12, the coil temperature, the temperature of the subcooled zone 14 and the corresponding saturated pressure, the enthalpy value of the inlet and outlet of the superheated zone 12, the enthalpy value of the inlet and outlet of the two-phase zone 13 and the enthalpy value of the inlet and outlet of the subcooled zone 14 are obtained through the enthalpy value calculation logic (step S72), and the enthalpy difference of the inlet and outlet of each zone is calculated based on this to obtain the enthalpy difference ratio between each zone (step S73).

[0121] It can be known that the pressures in the supercooling zone 14 and the superheating zone 12 can also be detected by pressure sensors arranged at these locations.

[0122] According to the above, the enthalpy difference between the inlet and outlet of the superheating zone 12 is:

[0123] H 过热区 =f1(t 进口 , p 进口 , t 盘管 , p 盘管 )

[0124] Among them, t 进口 is the inlet temperature of the superheated zone 12, p 进口 is the inlet pressure of the superheated zone 12, t 盘管 is the coil temperature, p 盘管 is the coil pressure, and f1 is the function for calculating the enthalpy difference.

[0125] The calculation process of the above formula is to first use t 进口 and p 进口 Calculate the enthalpy H at the inlet of superheated zone 12 过热进 , using t 盘管 and p 盘管 Calculate the enthalpy H at the outlet of superheated zone 12 过热出 Then the enthalpy difference between the inlet and outlet of the superheating zone 12 is obtained.

[0126] It should be noted that in this embodiment, the coil temperature is used as the outlet temperature of the superheat zone 12, and the coil pressure is used as the outlet pressure of the superheat zone 12. The temperature detected by the third temperature sensor 93, located on the side of the second expansion valve 71 near the indoor heat exchanger 11, is used as the inlet temperature of the superheat zone 12, and the pressure at this location is used as the outlet pressure of the superheat zone 12.

[0127] The enthalpy difference between the inlet and outlet of the two-phase region 13 is:

[0128] H 两相区 =f1(t 盘管 , p 盘管 , t 盘管 , p 盘管 )

[0129] Among them, t 进口 is the inlet temperature of the superheated zone 12, p 进口 is the inlet pressure of the superheated zone 12, t 盘管 is the coil temperature, p 盘管 is the coil pressure, and f1 is the function for calculating the enthalpy difference.

[0130] The calculation process of the above formula is to first use t 盘管 and p 盘管 Calculate the enthalpy H at the superheat zone inlet 两相进 , using t 盘管 and p 盘管 Calculate the enthalpy H at the outlet of superheated zone 12 两相出 Then the enthalpy difference between the inlet and outlet of the two-phase region 13 is obtained.

[0131] It should be noted that calculation of the enthalpy value at a certain position based on temperature and pressure is achievable by those skilled in the art and will not be elaborated in this application.

[0132] The enthalpy difference between the inlet and outlet of the supercooling zone 14 is:

[0133] H 过冷区 =f1(t 盘管 , p 盘管 , t 出口 , p 出口 )

[0134] Among them, t 出口 is the outlet temperature of the supercooling zone 14, p 出口 is the outlet pressure of the supercooling zone 14, t 盘管 is the coil temperature, p 盘管 is the coil pressure, and f1 is the function for calculating the enthalpy difference.

[0135] The calculation process of the above formula is to first use t 盘管 and p 盘管 Calculate the enthalpy H at the inlet of the subcooling zone 14 过冷进 , using t 出口 and p 出口 Calculate the enthalpy H at the outlet of the subcooling zone 14 过冷出 Then the enthalpy difference between the inlet and outlet of the supercooling zone 14 is obtained.

[0136] It should be noted that in this embodiment, the coil temperature is used as the inlet temperature of the subcooling zone 14, and the coil pressure is used as the inlet pressure of the subcooling zone 14. The temperature detected by the second temperature sensor 92, located on the side of the first expansion valve 61 near the indoor heat exchanger 11, is used as the outlet temperature of the subcooling zone 14, and the pressure at this location is used as the outlet pressure of the subcooling zone 14.

[0137] In some implementations of this embodiment, the average refrigerant density of the superheated region 12, the two-phase region 13, and the supercooled region 14 is calculated using the average refrigerant density calculation;

[0138] Specifically, in the calculation of the average refrigerant density, the average refrigerant density of the corresponding area is calculated based on the enthalpy values ​​of the inlet and outlet of the corresponding area.

[0139] According to the above, the average density of the refrigerant in the superheated zone 12 is:

[0140] ρ 过热 =f2((H 过热进 +H 过热出 ) / 2)

[0141] Among them, ρ 过热 is the average density of the refrigerant in the superheated zone 12, H 过热进 is the outlet enthalpy of the superheated zone 12, H 过热出 is the inlet enthalpy value of the superheated zone 12, and f2 is the function for calculating the average density of the refrigerant.

[0142] The average density of the refrigerant in the two-phase region 13 is:

[0143] ρ 两相 =f2((H 两相进 +H 两相出 ) / 2)

[0144] Among them, ρ 两相 is the average density of the refrigerant in the two-phase region 13, H 两相进 is the outlet enthalpy of the superheated zone 12, H 两相出 is the inlet enthalpy value of the superheated zone 12, and f2 is the function for calculating the average density of the refrigerant.

[0145] The average density of the refrigerant in the supercooling zone 14 is:

[0146] ρ 过冷 =f2((H 过冷进 +H 过冷出 ) / 2)

[0147] Among them, ρ 过冷 is the average density of the refrigerant in the supercooling zone 14, H 过热进 is the outlet enthalpy of the superheated zone 12, H 过热出 is the inlet enthalpy of the superheated zone 12, and f2 is the function for calculating the average density of the refrigerant

[0148] In some implementations of this embodiment, the above-mentioned first logical operation is to obtain the total refrigerant average density of the one-to-many air conditioner 100 based on the calculated volume proportions of the supercooling zone 14, the superheating zone 12 and the two-phase zone 13 in the indoor heat exchanger 11 and the average density of the refrigerant; and to obtain the required total volume of the indoor heat exchanger 11 based on the total refrigerant average density, the total refrigerant amount, and the distribution ratio coefficient of the refrigerant in the indoor heat exchanger 11 under heating conditions.

[0149] It should be noted that the average refrigerant density and volume proportion of each zone of the entire one-to-many air conditioner can be obtained based on the average refrigerant density and volume proportion of each zone of the indoor heat exchanger, thereby obtaining the total average refrigerant density of the one-to-many air conditioner.

[0150] Specifically, the average density of the total refrigerant in a one-to-many air conditioner system is:

[0151] ρ=ρ 过热 *A+ρ 两相 *B+ρ 过冷 *C

[0152] Wherein, ρ is the average density of the total refrigerant of the entire one-to-many air conditioner 100, A is the volume ratio of the superheated area 12 of the entire one-to-many air conditioner 100, B is the volume ratio of the two-phase area 13 of the entire one-to-many air conditioner 100, C is the volume ratio of the supercooled area 14 of the entire one-to-many air conditioner 100, ρ 过热 is the average density of refrigerant in the superheated zone 12 of the entire one-to-many air conditioner 100, ρ 两相 is the average density of the refrigerant in the two-phase region 13 of the entire one-to-many air conditioner 100, ρ 过冷 It is the average density of the refrigerant in the supercooling zone 14 of the entire one-to-many air conditioner 100.

[0153] It should be noted that the enthalpy difference ratio between the zones is obtained according to the enthalpy difference between the zones, and the enthalpy difference ratio between the zones can be used as the volume ratio of the zones.

[0154] Specifically, the total volume of the indoor heat exchanger 11 required for the current one-to-many air conditioner 100 is:

[0155] J=K1*G 冷媒量 / ρ

[0156] Wherein, J is the total volume of the indoor heat exchanger 11, ρ is the total average density of the refrigerant in the entire one-to-many air conditioner 100, and K1 is the distribution ratio coefficient of the refrigerant in the condenser under heating conditions. For example, K1 can be set to 31%-38%.

[0157] In some implementations of this embodiment, reference Figure 8First, after adjusting the first expansion valve 61 and / or the second expansion valve 71 (step S81), the actual subcooling degree CSC at this time is calculated, and based on this, the average subcooling degree CSCavg of each indoor heat exchanger 11 after startup is calculated (step S82);

[0158] Determine the relationship between the average supercooling degree CSCavg and the target supercooling degree range (step S83);

[0159] In step S83, when the average subcooling degree CSCavg is within the target subcooling degree range, step S84 is executed, and there is no need to adjust the expansion valve again;

[0160] In step S83, if the average subcooling degree CSCavg is not within the target subcooling degree range, step S85 is executed to adjust the opening of the first expansion valve 61 and / or the second expansion valve 71 again to adjust the amount of refrigerant flowing through the indoor heat exchanger 11 per unit time. For example, the target subcooling degree range is [5, 20].

[0161] Specifically, when the average subcooling degree is greater than the upper limit of the target subcooling degree range, the expansion valve opening is decreased by a set number of steps; when the average subcooling degree is less than the lower limit of the target subcooling degree range, the expansion valve opening is increased by a set number of steps.

[0162] Specifically, the set number of steps may be set to be related to the difference between the average subcooling degree and the target subcooling degree range.

[0163] More specifically, when the average subcooling degree is greater than the upper limit of the target subcooling degree range, the number of steps is set in relation to the difference ΔT1 between the average subcooling degree and the upper limit of the target subcooling degree range.

[0164] When the average subcooling degree is less than the lower limit of the target subcooling degree, the number of steps is set to be related to the difference ΔT2 between the average subcooling degree and the lower limit of the target subcooling degree range. For example, the opening is increased and the number of steps is set to 1.5ΔT2.

[0165] Through the above settings, the on-off status of each refrigerant branch in the refrigerant circulation loop is controlled by the dual electronic expansion valve system, and the valve can be dynamically adjusted according to the supercooling degree, which can effectively solve the heat leakage problem of the indoor unit in the off state and improve the indoor heating comfort.

[0166] It can be known that the target superheat range is stored in the memory 82 of the controller 8 .

[0167] It should be noted that subcooling refers to the difference between the condensing water temperature at a certain pressure and the saturation temperature at the corresponding pressure. The subcooling in this application refers to the heating condensing subcooling. The heating condensing subcooling is only adjusted when the one-to-many air conditioner 100 is operating with some indoor units 1 in operation. In other words, the above control logic regulates and controls the expansion valve when it is shut down or credited during partial operation, and does not adjust it during full operation.

[0168] The above-mentioned supercooling CSC calculation formula is as follows:

[0169] CSC=T _c_max -T 液管

[0170] Where CSC is the actual supercooling, T _c_max is the maximum coil temperature in indoor unit 1, T 液管 is the liquid pipe temperature of indoor unit 1.

[0171] In some implementations of this embodiment, a fifth temperature sensor 95 is further included, which is provided on the indoor heat exchanger 11 and is used to detect the liquid pipe temperature;

[0172] The controller 8 is configured to obtain an actual subcooling degree of the corresponding indoor heat exchanger 11 according to the maximum coil temperature and liquid pipe temperature in each indoor heat exchanger 11 under heating conditions.

[0173] In some implementations of this embodiment, in the heating mode, when the working status of each indoor unit 1 changes, the corresponding expansion valve of the indoor unit 1 that is shut down or on standby can first be operated with a calculated initial valve opening, and then the above-mentioned expansion valve adjustment can be performed after the working set time.

[0174] Specifically, the controller 8 is configured as follows: during the operation of the heating mode of the one-to-many air conditioner 100, when the switch state of the indoor heat exchanger 11 changes, an initial valve opening calculation is performed according to the outdoor ambient temperature and the frequency of the compressor 4, and the opening of the first expansion valve 61 and / or the second expansion valve 71 corresponding to the indoor heat exchanger 11 in the shutdown state or standby state is adjusted according to the calculated initial valve opening, and the opening is maintained for a period of time before the expansion valve opening is corrected.

[0175] In some implementations of this embodiment, the initial valve opening is also related to the number of indoor heat exchangers 11 that are turned on and the heating capacity of the one-to-many air conditioners 100.

[0176] The following describes the calculation process of the initial valve opening of the expansion valve.

[0177] The calculation formula for the initial valve opening is:

[0178] M=K0*K2*(Fr*kfrh+M0)*[1+(T外ami -7)*K out ]

[0179] Among them, M is the initial valve opening, K0 is the startup quantity correction coefficient, K2 is the expansion valve caliber correction coefficient, Fr is the current operating frequency of compressor 4, kfrh is the heating frequency correction coefficient, M0 is the rated initial opening, T 外ami is the outdoor ambient temperature, K out is the outdoor ambient temperature correction factor.

[0180] It should be noted that the value selection rule of K0 is the same in the cooling mode and the heating mode, and is stored in the memory 82 of the controller 8. The range of K0 is set to (0.00-2.00).

[0181] For example, taking six indoor units 1 as an example, referring to the table below, when there is only one active unit, K0 is 1.00; when there are two active units, K0 is 0.85; when there are three active units, K0 is 0.7; when there are four active units, K0 is 0.6; and when there are five active units, K0 is 0.5. It should be noted that these are examples and can be adjusted in actual use.

[0182] Number of boots <![CDATA[K0]]> one 1.00 two 0.85 three 0.70 Four 0.60 five 0.50

[0183] K2 is used when expansion valves of different diameters exist and is stored in the memory 82 of the controller 8 .

[0184] When using Fr, rounding is adopted to take the integer multiple of 10.

[0185] The range of kfrh is set to (0.00-2.00). For example, kfrh is set to 0.6. kfrh is stored in the memory 82 of the controller 8.

[0186] M0 is the rated initial opening. The value of the rated initial opening is related to the rated initial power of the indoor unit 1 in the heating mode. The rated initial opening is determined in the memory 82 according to the capacity of the indoor unit 1. Specifically, when the rated initial power is 0-2800W, the rated initial opening is 100 steps; when the rated initial power is 2801W-3600W, the rated initial opening is 120 steps; when the rated initial power is 3601W-5100W, the rated initial opening is 180 steps; when the rated initial power is 5101W-6400W, the rated initial opening is 200 steps; and when the rated initial power is 6401W or above, the rated initial opening is 220 steps.

[0187] K out The range is (0.000-0.050), for example, K outIt can be set to 0.020, and the outdoor ambient temperature correction coefficient is stored in the memory 82 of the controller 8.

[0188] In some implementations of this embodiment, while the first expansion valve 61 or the second expansion valve 71 corresponding to the indoor heat exchanger 11 is operating at an initial valve opening, if the operating frequency of the compressor 4 changes by more than a set change condition, the initial valve opening is recalculated. For example, the set change condition is that the operating frequency of the compressor 4 changes by more than 10 Hz.

[0189] Specifically, when calculating the initial valve opening or when the expansion valve operates at the initial valve opening and before adjusting the initial valve opening, when the operating frequency of the compressor 4 changes more than the set change condition, the initial valve opening needs to be recalculated.

[0190] Reference Figure 9 , taking four indoor units 1 as an example to illustrate the control logic of the one-to-many air conditioner 100 in this application.

[0191] When the one-to-many air conditioner 100 is in heating mode, some indoor units 1 are in the on state, and some indoor units 1 are in the off state, and work for a period of time (step S91); for example, it can be set to work for 30 seconds and then turn on to adjust the opening of the electronic expansion valve of the indoor unit 1 that is in the off state.

[0192] Detect the coil temperature, the temperature of the superheating zone 12, and the temperature of the subcooling zone 14, and calculate the required total volume of the indoor heat exchanger 11 based on the total refrigerant amount and the refrigerant distribution ratio coefficient in the indoor unit 1 under heating conditions (step S92);

[0193] A new switch combination is obtained based on the required total volume of the indoor heat exchanger 11, the volumes of the four indoor units 1, and the switch combination, and the working state of the expansion valve corresponding to the indoor unit 1 that is not turned on is adjusted accordingly (step S93);

[0194] Determine whether the average supercooling degree of the one-to-many air conditioners 100 is within the target supercooling degree range (step S94);

[0195] In step S94, when the average subcooling degree CSCavg is within the target subcooling degree range, step S95 is executed and the expansion valve does not need to be adjusted again;

[0196] In step S94 , when the average degree of supercooling CSCavg is not within the target degree of supercooling range, step S96 is executed, and the opening of the first expansion valve 61 and / or the second expansion valve 71 needs to be adjusted again.

[0197] Reference Figure 10, which illustrates the control logic of first operating the expansion valve of the indoor unit 1 in the on state at the initial valve opening before adjusting the expansion valve opening.

[0198] The one-to-many air conditioner 100 executes the heating mode, and determines whether some indoor units 1 are in the on state and some indoor units 1 are in the off state (step S101); determines whether the switch state of the indoor units 1 of the one-to-many air conditioner 100 changes (step S110);

[0199] In step S110, if the switch state changes, step S102 is executed to calculate the initial valve opening, and the opening of the expansion valve of the indoor unit 1 that is not turned on is controlled based on the initial valve opening;

[0200] In step S110, if the switch state has not changed, step S103 is executed without adjusting the opening of the expansion valve;

[0201] Determine whether the one-to-many air conditioner 100 has been operating for 5 minutes at the initial valve opening calculated in step S102 (step S104);

[0202] If the target value is reached in step 104, step S105 is executed to calculate a new opening combination and adjust the working state of the expansion valve accordingly; then step S106 is executed to calculate the average subcooling degree of the multi-use air conditioner 100 at this time; and it is determined whether the average subcooling degree is within the target subcooling degree range (step S107);

[0203] In step S107, when the average subcooling degree CSCavg is within the target subcooling degree range, step S108 is executed and there is no need to adjust the expansion valve again;

[0204] In step S107, when the average supercooling degree CSCavg is not within the target supercooling degree range, step S109 is executed, and the opening of the first expansion valve 61 and / or the second expansion valve 71 needs to be adjusted again to adjust the amount of refrigerant running in the air-conditioning system so that the air-conditioning system reaches the optimal operating state.

[0205] In step S104, if it is not reached, then continue to execute step S104.

[0206] Through the above steps, during the operation of the cooling mode, the number of indoor units 1 that are turned on or off increases or decreases, and the initial valve openings of the expansion valves of all indoor units 1 need to be recalculated; after working for a period of time with the recalculated initial valve openings, the openings of the expansion valves of the indoor units 1 that are not turned on, the target exhaust superheat correction control and the equalizing liquid pipe control are adjusted.

[0207] Before adjusting the expansion valve opening of the indoor unit 1 that is not turned on, the initial valve opening is first calculated. The expansion valve can first be operated in a working mode that is more suitable for the current state to maintain the heating capacity and overall stability of the one-to-many air conditioner 100 system.

[0208] In the above embodiment, the one-to-many air conditioner 100 proposed in the present application includes a compressor 4, a four-way valve 5, an outdoor heat exchanger 21, a first valve unit 6, an indoor unit group 1 and a second valve unit 7 connected in series in sequence, the first valve unit 6 includes a plurality of first electronic expansion valves in parallel, the indoor unit group 1 includes a plurality of indoor heat exchangers 11 in parallel, the second valve unit 7 includes a plurality of second electronic expansion valves in parallel, the second expansion valve 71, the first expansion valve 61 and the indoor heat exchanger 11 correspond one to one to control the refrigerant flow through the indoor heat exchanger 11, and also includes a first temperature sensor 91 for detecting the coil temperature, a second temperature sensor 92 for detecting the temperature of the supercooling zone 14 and a third temperature sensor 93 for detecting the temperature of the superheating zone 12. The controller 8 is configured as follows: when the one-to-many air conditioner 100 is running in heating mode, when part of the indoor heat exchanger 11 is at After a period of time in the shutdown or standby state, the enthalpy difference ratio calculation and the refrigerant average density calculation of the supercooling zone 14, the superheating zone 12 and the two-phase zone 13 are performed based on the temperature of the superheating zone 12, the temperature of the supercooling zone 14 and the coil temperature. The enthalpy difference ratio is used to define the volume ratio of the supercooling zone 14, the superheating zone 12 and the two-phase zone 13 in the indoor heat exchanger 11; the required total volume of the indoor heat exchanger 11 is calculated through a first logical operation according to the total refrigerant amount, the distribution ratio coefficient of the refrigerant in the indoor heat exchanger 11 under heating conditions, the volume ratio and the average density of the refrigerant; the opening combination calculation is performed according to the total volume of the indoor heat exchanger 11, the volume of each indoor heat exchanger 11 and the switch state, and the opening size of the first expansion valve 61 and / or the second expansion valve 71 corresponding to the indoor heat exchanger 11 in the shutdown or standby state is adjusted according to the opening combination to adjust the heat leakage of the indoor unit 1.

[0209] The one-to-many air conditioner 100 of the present application adds an electronic expansion valve on the refrigerant loop, which corresponds to the electronic expansion valves of the original outdoor units 2. In the heating mode, the volume of the current combined indoor heat exchanger 11 is calculated according to the number of started units and the indoor and outdoor temperatures, and then the electronic expansion valves of the indoor units 1 of an appropriate number are intelligently switched on and off according to the volume value in each indoor heat exchanger 11, so as to reduce the heat leakage of the indoor units that are not turned on, and improve the heating performance and heating comfort of the system.

[0210] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A one-to-many air conditioner, characterized in that: include: A plurality of indoor units arranged in parallel, each including an indoor heat exchanger; an outdoor unit comprising a compressor and an outdoor heat exchanger connected in series with the indoor heat exchanger; a first valve unit connected between the indoor heat exchanger and the outdoor heat exchanger and comprising a plurality of first expansion valves arranged in parallel; a second valve assembly connected between the compressor and the indoor heat exchanger and comprising a plurality of second expansion valves arranged in parallel, wherein the second expansion valves, the first expansion valves, and the indoor heat exchanger correspond one to one to control a flow rate of refrigerant flowing through the indoor heat exchanger; a first temperature sensor, which is provided on the indoor heat exchanger and is used to detect the coil temperature of the indoor heat exchanger; a second temperature sensor, which is provided on a side of the first expansion valve close to the indoor heat exchanger, and is used to detect the temperature of a subcooling zone of the indoor heat exchanger under heating conditions; a third temperature sensor, which is provided on a side of the second expansion valve close to the indoor heat exchanger, and is used to detect the temperature of the superheat zone of the indoor heat exchanger under heating conditions; The controller is configured to: when the one-to-many air conditioner operates in a heating mode, after some of the indoor heat exchangers are in a shutdown or standby state for a period of time, perform an enthalpy difference ratio calculation of the subcooling zone, the superheating zone, and the two-phase zone and an average refrigerant density calculation based on the superheating zone temperature, the subcooling zone temperature, and the coil temperature, wherein the enthalpy difference ratio is used to define a volume ratio of the subcooling zone, the superheating zone, and the two-phase zone in the indoor heat exchanger; Obtaining a total refrigerant average density of the one-to-many air conditioner according to the calculated volume proportions of the subcooling zone, the superheating zone, and the two-phase zone in the indoor heat exchanger and the refrigerant average density; The required total volume of the indoor heat exchanger is calculated based on the total refrigerant average density, the total refrigerant volume, and the distribution ratio coefficient of the refrigerant in the indoor heat exchanger under heating conditions; wherein the distribution ratio coefficient of the refrigerant in the indoor heat exchanger under heating conditions is set to 31%-38%; An opening combination calculation is performed based on the total volume of the indoor heat exchangers, the volume of each indoor heat exchanger, and the switch status. The opening size of the first expansion valve and / or the second expansion valve corresponding to the indoor heat exchanger in the shutdown or standby state is adjusted according to the opening combination to adjust the heat leakage of the indoor unit.

2. The one-to-many air conditioner according to claim 1, characterized in that: In the enthalpy difference ratio calculation: Determining a corresponding saturation pressure according to the superheating zone temperature, the subcooling zone temperature, and the coil temperature; According to the superheating zone temperature, the coil temperature, the supercooling zone temperature and the corresponding saturation pressure, the enthalpy value of the inlet and outlet of the superheating zone, the enthalpy value of the inlet and outlet of the two-phase zone and the enthalpy value of the inlet and outlet of the supercooling zone are obtained through the enthalpy calculation logic, and the enthalpy difference of the inlet and outlet of each zone is calculated accordingly to obtain the enthalpy difference ratio of each zone.

3. The one-to-many air conditioner according to claim 2, characterized in that: Calculating the average refrigerant density of the superheated zone, the two-phase zone, and the supercooled zone respectively using the average refrigerant density calculation; In the calculation of the average refrigerant density, the average refrigerant density of the corresponding area is calculated based on the enthalpy values ​​of the inlet and outlet of the corresponding area.

4. The one-to-many air conditioner according to claim 1, characterized in that: Also included is a fourth temperature sensor, which is provided on the outdoor unit and is used to detect the outdoor ambient temperature; The controller is configured to: during the operation of the heating mode of the one-to-many air conditioner, when the on-off state of the indoor heat exchanger changes, perform an initial valve opening calculation based on the outdoor ambient temperature and the compressor frequency, adjust the opening of the first expansion valve and / or the second expansion valve corresponding to the indoor heat exchanger in the shutdown state or the standby state based on the calculated initial valve opening, and maintain the opening for a period of time before adjusting the expansion valve opening.

5. The one-to-many air conditioner according to claim 4, characterized in that: The initial valve opening is also related to the number of indoor heat exchangers that are turned on and the heating capacity of the one-to-many air conditioner.

6. The one-to-many air conditioner according to claim 1, characterized in that: After adjusting the first expansion valve and / or the second expansion valve, calculating the actual subcooling degree at that time, and calculating the average subcooling degree of each of the indoor heat exchangers after startup based on the actual subcooling degree; When the average degree of subcooling is not within the target degree of subcooling, the opening of the first expansion valve and / or the second expansion valve is adjusted again to adjust the amount of refrigerant flowing through the indoor heat exchanger per unit time.

7. The one-to-many air conditioner according to claim 6, characterized in that: Also included is a fifth temperature sensor, which is provided on the indoor heat exchanger and is used to detect the temperature of the liquid pipe; The controller is configured to obtain an actual subcooling degree corresponding to the indoor heat exchanger according to a maximum coil temperature and a liquid pipe temperature in each indoor heat exchanger under a heating condition.

8. The one-to-many air conditioner according to claim 1, characterized in that: When the first expansion valve or the second expansion valve corresponding to the indoor heat exchanger in the shutdown or standby state is operating at an initial valve opening, when the operating frequency of the compressor changes more than a set change condition, the initial valve opening is recalculated.

9. The one-to-many air conditioner according to claim 7, characterized in that: The first expansion valve includes a stepper motor and a slider. The controller controls the operation of the stepper motor according to a preset program. The motor rotor of the stepper motor directly drives the slider to move, thereby changing the refrigerant flow rate passing through the first expansion valve. During the process of adjusting the opening of the first expansion valve, the adjustment is performed with a set number of steps each time.

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