Air conditioning system

Abstract

The application provides an air conditioning system, comprising an outdoor unit, an indoor unit and a refrigerant cutoff device, the refrigerant cutoff device is connected with the outdoor unit through an outdoor unit side liquid pipe and an outdoor unit side gas pipe, and is connected with the indoor unit through an indoor unit side liquid pipe and an indoor unit side gas pipe, and the refrigerant cutoff device comprises first and second cutoff device throttling elements arranged on the liquid pipe side and the gas pipe side; a processing device is configured to: estimate a temperature change rate of an air conditioning room where the indoor unit is located, and an offset degree of a temperature of the air conditioning room from a target temperature; estimate a target refrigerant temperature matched with a current load of the air conditioning room based on the temperature change rate and the offset degree; and estimate the opening degrees of an indoor electronic expansion valve, the first cutoff device throttling element and the second cutoff device throttling element based on the target refrigerant temperature, a preset target superheat degree or a target subcooling degree. The application improves energy utilization efficiency, thereby comprehensively optimizing the performance, comfort and energy efficiency of the air conditioning system.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and more particularly to an air conditioning system. Background Technology

[0002] In the field of refrigeration, load usually refers to the amount of heat that a refrigeration system needs to remove (cooling mode) or provide (heating mode) to maintain the required indoor environmental conditions.

[0003] In multi-split air conditioning systems, indoor units may experience overshoot under low load conditions. Overshoot refers to the phenomenon where the temperature or other controlled parameters exceed the setpoint, which is undesirable in the response of the control system.

[0004] Under low-load conditions, indoor units are prone to over-temperature adjustment. This is due to two main reasons: firstly, the control system's response to small load changes may be insufficient or too slow, resulting in a delay in refrigerant flow regulation, causing it to continue cooling or heating even after the set temperature has been reached; secondly, the system design may not have adequately considered the load matching of each indoor unit. For example, in practical applications, the load in some areas may be far lower than the system's design load, but the system still controls the refrigerant temperature to meet the highest load, leading to over-temperature adjustment in areas with lower loads. After over-temperature adjustment, the indoor units can only compensate for the impact by continuously adjusting the refrigerant flow through the indoor electronic expansion valve or by continuously adjusting the indoor fan to change the air circulation. However, the indoor environment has a certain thermal inertia, and users will experience discomfort for a period of time, affecting the user experience. Summary of the Invention

[0005] This application provides an air conditioning system designed to prevent over-adjustment of indoor units in multi-split systems under low-load conditions.

[0006] In one or more embodiments of this application, the air conditioning system includes an outdoor unit and an indoor unit, wherein the outdoor unit includes a compressor and an outdoor heat exchanger; and the indoor unit includes an indoor heat exchanger and an indoor electronic expansion valve.

[0007] In one or more embodiments of this application, the air conditioning system further includes: a refrigerant shut-off device, which is connected to the outdoor unit via an outdoor unit-side liquid piping and an outdoor unit-side gas piping, and to the indoor unit via an indoor unit-side liquid piping and an indoor unit-side gas piping.

[0008] In one or more embodiments of this application, the refrigerant shut-off device includes: a first shut-off device throttling element and a second shut-off device throttling element; the first shut-off device throttling element is disposed between the liquid piping on the outdoor unit side and the liquid piping on the indoor unit side; the second shut-off device throttling element is disposed between the gas piping on the outdoor unit side and the gas piping on the indoor unit side.

[0009] In one or more embodiments of this application, the air conditioning system further includes: a processing device configured to: estimate the rate of temperature change of the air-conditioned room where the indoor unit is located, and the degree of deviation of the air-conditioned room temperature from the target temperature; estimate a target refrigerant temperature matching the current load of the air-conditioned room based on the rate of temperature change and the degree of deviation; and estimate the opening degree of the indoor electronic expansion valve, the first shut-off device throttling element, and the second shut-off device throttling element based on the target refrigerant temperature and a preset target superheat or target subcooling.

[0010] In one or more embodiments of this application, the air conditioning system includes multiple indoor units, and the number of refrigerant shut-off devices may be less than the number of indoor units.

[0011] In one or more embodiments of this application, the air conditioning system includes multiple indoor units, and the number of refrigerant shut-off devices is the same as the number of indoor units.

[0012] In one or more embodiments of this application, in a cooling mode, the processing device is configured to perform the following steps when estimating the opening degree of the indoor electronic expansion valve, the first shut-off device throttling element, and the second shut-off device throttling element based on the target refrigerant temperature, a preset target superheat, or a target subcooling: controlling the first shut-off device throttling element to its maximum opening degree; acquiring the real-time indoor heat exchanger refrigerant temperature, estimating the opening degree of the indoor electronic expansion valve based on the target refrigerant temperature and the real-time indoor heat exchanger refrigerant temperature; acquiring the real-time indoor heat exchanger liquid pipe temperature and the real-time indoor heat exchanger gas pipe temperature, calculating the refrigerant superheat based on the indoor heat exchanger liquid pipe temperature and the real-time indoor heat exchanger gas pipe temperature, and estimating the opening degree of the second shut-off device throttling element based on the target superheat and the refrigerant superheat.

[0013] In one or more embodiments of this application, the processing apparatus is configured to perform the following steps when estimating the opening of the indoor electronic expansion valve based on a target refrigerant temperature and a real-time indoor heat exchanger refrigerant temperature: when the target refrigerant temperature is higher than the real-time indoor heat exchanger refrigerant temperature, controlling the reduction of the opening of the indoor electronic expansion valve; when the target refrigerant temperature is lower than the real-time indoor heat exchanger refrigerant temperature, controlling the increase of the opening of the indoor electronic expansion valve; and when the target refrigerant temperature is equal to the real-time indoor heat exchanger refrigerant temperature, controlling the maintenance of the opening of the indoor electronic expansion valve.

[0014] In one or more embodiments of this application, the processing apparatus is configured to perform the following steps when estimating the opening degree of the throttling element of the second shut-off device based on the target superheat and the refrigerant superheat: when the refrigerant superheat is higher than the target superheat, controlling the opening degree of the throttling element of the second shut-off device to increase; when the refrigerant superheat is lower than the target superheat, controlling the opening degree of the throttling element of the second shut-off device to decrease; and when the refrigerant superheat is equal to the target superheat, controlling the opening degree of the throttling element of the second shut-off device to maintain it.

[0015] In one or more embodiments of this application, in heating mode, the processing device is configured to perform the following steps when estimating the opening degree of the indoor electronic expansion valve, the first shut-off device throttling element, and the second shut-off device throttling element based on the target refrigerant temperature, a preset target superheat, or a target subcooling: acquiring the real-time indoor heat exchanger refrigerant temperature; estimating the opening degree of the second shut-off device throttling element based on the target refrigerant temperature and the real-time heat exchanger refrigerant temperature; acquiring the real-time indoor heat exchanger liquid pipe temperature; calculating the refrigerant subcooling based on the real-time indoor heat exchanger liquid pipe temperature and the real-time heat exchanger refrigerant temperature; estimating the opening degree of the indoor electronic expansion valve based on the target subcooling and the refrigerant subcooling; and controlling the first shut-off device throttling element to be at its maximum opening degree.

[0016] In one or more embodiments of this application, the processing apparatus is configured to perform the following steps when estimating the opening degree of the throttling element of the second shut-off device based on the target refrigerant temperature and the real-time heat exchanger refrigerant temperature: when the real-time indoor heat exchanger refrigerant temperature is higher than the target refrigerant temperature, controlling the reduction of the opening degree of the throttling element of the second shut-off device; when the real-time indoor heat exchanger refrigerant temperature is lower than the target refrigerant temperature, controlling the increase of the opening degree of the throttling element of the second shut-off device; and when the real-time indoor heat exchanger refrigerant temperature is equal to the target refrigerant temperature, controlling the maintenance of the opening degree of the throttling element of the second shut-off device.

[0017] In one or more embodiments of this application, the processing apparatus is configured to perform the following steps when estimating the opening of the indoor electronic expansion valve based on the target subcooling and the refrigerant subcooling: when the refrigerant subcooling is higher than the target subcooling, controlling the opening of the indoor electronic expansion valve to increase; when the refrigerant subcooling is lower than the target subcooling, controlling the opening of the indoor electronic expansion valve to decrease; and when the refrigerant subcooling is equal to the target subcooling, controlling the opening of the indoor electronic expansion valve to remain constant.

[0018] In one or more embodiments of this application, the processing device is configured to estimate the rate of temperature change of the air-conditioned room where the indoor unit is located, and the degree of deviation of the air-conditioned room temperature from the target temperature; and to estimate a target refrigerant temperature that matches the current load of the air-conditioned room based on the rate of temperature change, the degree of deviation, and a preset data table.

[0019] In one or more embodiments of this application, the processing device is further configured to shut down the first and second shut-off throttling elements in the refrigerant shut-off device corresponding to the indoor unit when the refrigerant concentration in the air-conditioned room exceeds a set threshold.

[0020] The air conditioning system provided in this application has multiple advantages in solving the problem of over-adjustment of indoor units under low-load conditions: First, through the throttling elements of the first and second cut-off devices in the refrigerant cut-off device, the air conditioning system can accurately adjust the refrigerant flow and temperature, avoiding temperature fluctuations caused by over-adjustment or under-adjustment; Second, by estimating the rate of temperature change and the degree of deviation from the target temperature in real time, the target refrigerant temperature is intelligently generated, ensuring that the control target matches the real-time load and avoiding user experience loss due to control delays and thermal inertia; In addition, the air conditioning system optimizes the adjustment according to the current load matching situation, improving energy utilization efficiency, thereby comprehensively optimizing the performance, comfort, and energy efficiency of the air conditioning system.

[0021] Other features and advantages of the present invention will become clearer after reading the detailed embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1This is a schematic diagram of the structure of an air conditioning system provided in one or more embodiments of this application;

[0024] Figure 2 This is a schematic diagram of the structure of an air conditioning system provided in one or more embodiments of this application;

[0025] Figure 3 This is a schematic diagram of the structure of an air conditioning system provided in one or more embodiments of this application;

[0026] Figure 4 This is an installation diagram of an air conditioning system provided in one or more embodiments of this application;

[0027] Figure 5 This is an example of a curve showing the temperature change over time in an air-conditioned room under cooling mode;

[0028] Figure 6 This is an example of a data table in cooling mode;

[0029] Figure 7 This is an installation diagram of an air conditioning system provided in one or more embodiments of this application;

[0030] Figure 8 This is an example of a data table in cooling mode;

[0031] Figure 9 This is an example of the target refrigerant temperature change using rooms 1 and 2 as examples;

[0032] Figure 10 This is an example of a curve showing the temperature change over time in an air-conditioned room under heating mode.

[0033] Figure 11 This is an example of a data table in heating mode;

[0034] Figure 12 This is an installation diagram of an air conditioning system provided in one or more embodiments of this application;

[0035] Figure 13 This is an example of a data table in heating mode;

[0036] Figure 14 This is a list example of the target heating agent temperature changes using rooms 1 and 2 as examples;

[0037] Figure 15 This is a schematic diagram of the structure of an air conditioning system provided in one or more embodiments of this application;

[0038] Figure 16 This is an installation diagram of an air conditioning system provided in one or more embodiments of this application;

[0039] Figure 17 This is a schematic diagram of the structure of the processing device of the air conditioning system provided in one or more embodiments of this application;

[0040] In the diagram: 1. Compressor; 2. Oil separator; 2'. Check valve; 3. Gas-liquid separator; 4. Switching valve; 5. Outdoor fan; 6. Outdoor heat exchanger; 7. Outdoor electronic expansion valve; 8. Liquid pipe shut-off valve; 9. Gas pipe shut-off valve; 10. First shut-off valve; 11. Second shut-off valve; 12. First shut-off device throttling element; 13. Second shut-off device throttling element; 14. Third shut-off valve; 15. Fourth shut-off valve; 16. Indoor side liquid pipe shut-off valve; 17. Indoor side gas pipe shut-off valve; 18. Indoor electronic expansion valve; 19. Indoor heat exchanger; 20. Indoor fan; 21. First shut-off valve; 22. Second shut-off valve; 23. First... 24. Throttling element of the second shut-off device; 25. Third shut-off valve; 26. Fourth shut-off valve; 27. Indoor side liquid pipe shut-off valve; 28. Indoor side gas pipe shut-off valve; 29. ​​Indoor electronic expansion valve; 30. Indoor heat exchanger; 31. Indoor fan; 32. First shut-off valve; 33. Second shut-off valve; 34. Throttling element of the first shut-off device; 35. Throttling element of the second shut-off device; 36. Third shut-off valve; 37. Fourth shut-off valve; 38. Indoor side liquid pipe shut-off valve; 39. Indoor side gas pipe shut-off valve; 40. Indoor electronic expansion valve; 41. Indoor heat exchanger; 42. Indoor fan; 43. First shut-off valve ; 44. Second shut-off valve; 45. Throttling element of first shut-off device; 46. Throttling element of second shut-off device; 47. Third shut-off valve; 48. Fourth shut-off valve; 49. Indoor liquid pipe shut-off valve; 50. Indoor gas pipe shut-off valve; 51. Indoor electronic expansion valve; 52. Indoor heat exchanger; 53. Indoor fan; 101. Outdoor unit; 102. Liquid pipe; 103. Gas pipe; 201. Refrigerant shut-off device; 202. Refrigerant shut-off device; 203. Refrigerant shut-off device; 204. Refrigerant shut-off device; 301. Indoor unit; 302. Indoor unit; 303. Indoor unit; 304. Indoor unit; 40 1. Buzzer; 402. Buzzer; 403. Buzzer; 404. Buzzer; 501. Refrigerant leak sensor; 502. Refrigerant leak sensor; 503. Refrigerant leak sensor; 504. Refrigerant leak sensor; 505. Coil temperature sensor; 506. Liquid line temperature sensor; 507. Gas line temperature sensor; 60. Processing device; 601. Processor; 602. Non-volatile memory; 603. Volatile memory; 604. Display device; 605. Operating device; 606. Communication interface; 607. Drive device; 608. Bus; 609. Storage medium; 610. Storage medium. Detailed Implementation

[0041] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0042] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0043] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "multiple" means two or more.

[0044] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0045] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0046] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and letters may be repeated in different examples; this repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and the use of other materials.

[0047] Hereinafter, one or more embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0048] Figure 1 This diagram illustrates the structure of an air conditioning system provided by one or more specific embodiments of the present invention.

[0049] The air conditioning system provided in this application is a multi-split system. A multi-split system is an air conditioning system that can independently heat or cool multiple rooms or zones, and the temperature of each room or zone can be controlled independently or in combination. Multi-split air conditioning systems are particularly suitable for buildings that require independent temperature control and include multiple rooms or zones, such as office buildings, schools, hotels, and large residences.

[0050] Multi-split air conditioning systems integrate a refrigeration cycle. This cycle utilizes a compressor, condenser, expansion valve, and evaporator. The refrigeration cycle comprises a series of processes involving compression, condensation, expansion, and evaporation to cool or heat an indoor space.

[0051] From a principle perspective, low-temperature, low-pressure refrigerant enters compressor 1, which compresses it into a high-temperature, high-pressure refrigerant gas and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser, where the condenser condenses the compressed refrigerant into a liquid phase, and the heat is released to the surrounding environment through the condensation process.

[0052] The throttling device expands the high-temperature, high-pressure liquid refrigerant that condenses in the condenser into a low-pressure liquid refrigerant. The evaporator evaporates the expanded refrigerant in the throttling device and returns the low-temperature, low-pressure refrigerant to compressor 1. The evaporator achieves a cooling effect by utilizing the latent heat of refrigerant evaporation to exchange heat with the material being cooled. Throughout the cycle, the air conditioning system regulates the temperature of the indoor space.

[0053] In one or more embodiments of this application, the air conditioning system includes an outdoor unit 101 and an indoor unit connected to each other.

[0054] In one or more embodiments of this application, the air conditioning system includes an outdoor unit 101 and four indoor units connected to each other, such as Figure 1 and Figure 4 As shown in Figures 301, 302, 303, and 304. However, in this application, there is no particular limitation on the number of indoor units. More or fewer indoor units can be arranged in an air conditioning system in the same manner as the indoor units shown in the figures.

[0055] The outdoor unit 101 and the indoor unit are connected by a liquid pipe 102 and a gas pipe 103. The liquid pipe 102 and the gas pipe 103 are used to supply refrigerant flow, so that the refrigerant can form a refrigerant circuit and circulate in it.

[0056] In one or more embodiments of this application, a liquid pipe shut-off valve 8 is provided on the liquid pipe 102.

[0057] In one or more embodiments of this application, an airway shut-off valve 9 is provided on the airway 103.

[0058] The basic structure and function of outdoor unit 101 are described below. When using the same system architecture, the number of outdoor units 101 in the air conditioning system can be expanded to multiple units, which can then operate in groups. The throttling device includes an outdoor electronic expansion valve 7, and outdoor units 101 are correspondingly configured with outdoor electronic expansion valves 7.

[0059] In one or more embodiments of this application, the outdoor unit 101 is part of the refrigeration cycle that includes the compressor 1 and the outdoor heat exchanger 6. The outdoor unit 101 can perform heating or cooling operation on the outdoor side to provide energy to the indoor unit for raising or lowering the indoor temperature.

[0060] In one or more embodiments of this application, an oil separator 2 is also provided in the outdoor unit 101. The function of the oil separator 2 in the air conditioning system is to separate lubricating oil and refrigerant. Since the compressor 1 requires lubricating oil to reduce friction and wear to ensure normal operation, the lubricating oil mixes with the refrigerant during compressor 1 operation. The oil separator 2 separates the lubricating oil from the refrigerant using a physical separation principle (e.g., centrifugal force or gravity). The separated lubricating oil is recovered and recycled, while the refrigerant continues to flow. The oil separator 2 is equipped with a one-way valve 2'.

[0061] In one or more embodiments of this application, a gas-liquid separator 3 is further provided in the outdoor unit 101. The gas-liquid separator 3 is based on the density difference between gas and liquid. When a refrigerant containing a mixture of gas and liquid enters the gas-liquid separator 3, the denser liquid refrigerant sinks due to gravity, while the less dense gas rises. In this way, the gas-liquid separator 3 can effectively separate liquid and gaseous refrigerant. The gas-liquid separator 3 is located on the suction side of the compressor 1, and it can also store excess refrigerant.

[0062] In one or more embodiments of this application, the outdoor unit 101 is further provided with a switching valve 4, which is typically a four-way valve, enabling the air conditioning system to switch between cooling mode and heating mode.

[0063] In one or more embodiments of this application, an outdoor fan 5 is further provided in the outdoor unit 101. The rotation speed of the outdoor fan 5 can be controlled to change the flow rate of air exchanging heat with the outdoor heat exchanger 6 by adjusting the rotation speed. The outdoor fan 5 can be an axial flow fan, a cross flow fan, or other optional fan types. The outdoor fan 5 is located near the outdoor heat exchanger 6.

[0064] In one or more embodiments of this application, the air conditioning system further includes a refrigerant shut-off device, as shown in figures 201, 202, 203, and 204. The refrigerant shut-off device is disposed between the outdoor unit 101 and the indoor unit. The refrigerant shut-off device is connected to the outdoor unit 101 on one hand through an outdoor unit-side liquid piping and an outdoor unit-side gas piping, and on the other hand, it is connected to the indoor unit on the other hand through an indoor unit-side liquid piping and an indoor unit-side gas piping.

[0065] In one or more embodiments of this application, the refrigerant shut-off device includes a first shut-off device throttling element, as shown in Figures 12, 23, 34 and 45, and a second shut-off device throttling element, as shown in Figures 13, 24, 35 and 46. The first shut-off device throttling element is disposed between the liquid piping on the outdoor unit side and the liquid piping on the indoor unit side, and the second shut-off device throttling element is disposed between the gas piping on the outdoor unit side and the gas piping on the indoor unit side.

[0066] In one or more embodiments of this application, the throttling element of the first shut-off device is an electronic expansion valve.

[0067] In one or more embodiments of this application, the throttling element of the second shut-off device is an electronic expansion valve.

[0068] In one or more embodiments of this application, a first shut-off valve is provided between the outdoor unit side liquid piping and the first shut-off device throttling element, as shown in Figures 10, 21, 32 and 43.

[0069] In one or more embodiments of this application, a second shut-off valve is provided between the outdoor unit-side gas piping and the throttling element of the second shut-off device, as shown in Figures 11, 22, 33 and 44.

[0070] In one or more embodiments of this application, a third shut-off valve is also provided between the indoor unit side liquid piping and the first shut-off device throttling element, as shown in Figures 14, 25, 36 and 47.

[0071] In one or more embodiments of this application, a fourth shut-off valve is also provided between the gas piping on the indoor unit side and the throttling element of the second shut-off device, as shown in Figures 15, 26, 37 and 48.

[0072] In one or more embodiments of this application, the refrigerant shut-off device can be housed separately in a housing and can be used in conjunction with an indoor unit.

[0073] In one or more embodiments of this application, the refrigerant shut-off device may be configured in conjunction with an indoor unit, or it may be configured in conjunction with only some indoor units.

[0074] In one or more embodiments of this application, an outdoor liquid pipe shut-off valve 8 and an indoor liquid pipe shut-off valve 16 are provided on the liquid pipe 102.

[0075] In one or more embodiments of this application, an outdoor air pipe shut-off valve 9 and an indoor air pipe shut-off valve 17 are provided on the air pipe 103.

[0076] The structure and function of the indoor units are described below, using one indoor unit as an example. The following description also applies to other indoor units.

[0077] The indoor unit utilizes the energy generated by the outdoor unit 101 to either increase or decrease the indoor temperature for cooling or heating operation. The indoor unit includes a connected indoor heat exchanger, as shown in figures 19, 30, 41, and 52, and an indoor electronic expansion valve, as shown in figures 18, 29, 40, and 51. The indoor heat exchanger and the indoor electronic expansion valve are correspondingly configured. The indoor electronic expansion valve is configured to reduce the refrigerant pressure and cause it to expand.

[0078] The indoor units are also equipped with indoor fans, as shown in figures 20, 31, 42, and 53. The indoor fans can be axial fans, cross-flow fans, or other types of fans. The indoor fans are located close to the indoor heat exchanger.

[0079] like Figure 2As shown, during refrigeration operation, the D port of the switching valve (taking a four-way valve as an example) is connected to the C port, and the E port is connected to the S port. The high-temperature and high-pressure gaseous refrigerant discharged by the compressor passes through the oil separator and the switching valve. The high-temperature and high-pressure gaseous refrigerant condenses into high-temperature and high-pressure liquid refrigerant in the outdoor heat exchanger. The high-temperature and high-pressure liquid refrigerant condensed by the outdoor heat exchanger passes through the outdoor electronic expansion valve and the outdoor side liquid pipe shut-off valve and is divided into multiple paths (for example, four paths as shown in the figure), which enter the refrigerant cut-off device corresponding to the indoor unit.

[0080] The high-temperature, high-pressure liquid refrigerant in the first part passes sequentially through the first shut-off valve 10, the first shut-off device throttling element 12, the third shut-off valve 14, the indoor liquid pipe shut-off valve 16, and the indoor electronic expansion valve 18, throttling the high-temperature, high-pressure liquid refrigerant into a low-temperature, low-pressure refrigerant. The low-temperature, low-pressure refrigerant evaporates into a low-temperature, low-pressure gaseous refrigerant in the indoor heat exchange 19. The low-temperature, low-pressure gaseous refrigerant passes sequentially through the indoor gas pipe shut-off valve 17, the fourth shut-off valve 15, and the second shut-off device throttling element 13, and then flows out from the second shut-off valve 11.

[0081] The high-temperature, high-pressure liquid refrigerant in the second part passes sequentially through the first shut-off valve 21, the first shut-off device throttling element 23, the third shut-off valve 25, the indoor liquid pipe shut-off valve 27, and the indoor electronic expansion valve 29, throttling the high-temperature, high-pressure liquid refrigerant into a low-temperature, low-pressure refrigerant. The low-temperature, low-pressure refrigerant evaporates into a low-temperature, low-pressure gaseous refrigerant in the indoor heat exchanger 30. The low-temperature, low-pressure gaseous refrigerant passes sequentially through the indoor gas pipe shut-off valve 28, the fourth shut-off valve 26, and the second shut-off device throttling element 24, and then flows out from the second shut-off valve 22.

[0082] The high-temperature, high-pressure liquid refrigerant in the third part passes sequentially through the first shut-off valve 32, the first shut-off device throttling element 34, the third shut-off valve 36, the indoor liquid pipe shut-off valve 38, and the indoor electronic expansion valve 40, throttling the high-temperature, high-pressure liquid refrigerant into a low-temperature, low-pressure refrigerant. The low-temperature, low-pressure refrigerant evaporates into a low-temperature, low-pressure gaseous refrigerant in the indoor heat exchanger 41. The low-temperature, low-pressure gaseous refrigerant passes sequentially through the indoor gas pipe shut-off valve 39, the fourth shut-off valve 37, and the second shut-off device throttling element 35, and then flows out from the second shut-off valve 33.

[0083] The high-temperature, high-pressure liquid refrigerant in the fourth part passes sequentially through the first shut-off valve 43, the first shut-off device throttling element 45, the third shut-off valve 47, the indoor liquid pipe shut-off valve 49, and the indoor electronic expansion valve 51, throttling the high-temperature, high-pressure liquid refrigerant into a low-temperature, low-pressure refrigerant. The low-temperature, low-pressure refrigerant evaporates into a low-temperature, low-pressure gaseous refrigerant in the indoor heat exchanger 52. The low-temperature, low-pressure gaseous refrigerant passes sequentially through the indoor gas pipe shut-off valve 50, the fourth shut-off valve 48, and the second shut-off device throttling element 46, and then flows out from the second shut-off valve 44.

[0084] The low-temperature, low-pressure gaseous refrigerant flowing out from the second shut-off valve (11, 22, 33, 44) merges and flows into the gas-liquid separator 3 through the outdoor gas pipe shut-off valve 9 and the switching valve 4. The low-temperature, low-pressure gaseous refrigerant flows out from the gas-liquid separator 3 and enters the suction port of the compressor 1, thus completing the refrigeration operation.

[0085] like Figure 3 As shown, during heating operation, the D port of the switching valve (taking a four-way valve as an example) is connected to the E port, and the C port is connected to the S port. The high-temperature and high-pressure gaseous refrigerant discharged by the compressor is divided into multiple paths after passing through the oil separator, the switching valve, and the outdoor gas pipe shut-off valve.

[0086] The high-temperature, high-pressure liquid refrigerant in the first part passes through the second shut-off valve 11, the second shut-off device throttling element 13, the fourth shut-off valve 15, and the indoor side gas pipe shut-off valve 17, and condenses into a high-temperature, high-pressure liquid refrigerant in the indoor heat exchanger 19. The high-temperature, high-pressure liquid refrigerant then passes sequentially through the indoor electronic expansion valve 18, the indoor side liquid pipe shut-off valve 16, the third shut-off valve 14, and the first shut-off device throttling element 12, and flows out from the first shut-off valve 10.

[0087] The high-temperature, high-pressure liquid refrigerant in the second part passes through the second shut-off valve 22, the second shut-off device throttling element 24, the fourth shut-off valve 26, and the indoor side gas pipe shut-off valve 28, and condenses into a high-temperature, high-pressure liquid refrigerant in the indoor heat exchanger 30. The high-temperature, high-pressure liquid refrigerant then passes sequentially through the indoor electronic expansion valve 29, the indoor side liquid pipe shut-off valve 27, the third shut-off valve 25, and the first shut-off device throttling element 23, and flows out from the first shut-off valve 21.

[0088] The high-temperature, high-pressure liquid refrigerant in the third part passes through the second shut-off valve 33, the second shut-off device throttling element 35, the fourth shut-off valve 37, and the indoor side gas pipe shut-off valve 39, and condenses into a high-temperature, high-pressure liquid refrigerant in the indoor heat exchanger 41. The high-temperature, high-pressure liquid refrigerant then passes sequentially through the indoor electronic expansion valve 40, the indoor side liquid pipe shut-off valve 38, the third shut-off valve 36, and the first shut-off device throttling element 34, and flows out from the first shut-off valve 32.

[0089] The high-temperature, high-pressure liquid refrigerant in the fourth part passes through the second shut-off valve 44, the second shut-off device throttling element 46, the fourth shut-off valve 48, and the indoor side gas pipe shut-off valve 50, and condenses into a high-temperature, high-pressure liquid refrigerant in the indoor heat exchanger 52. The high-temperature, high-pressure liquid refrigerant then passes sequentially through the indoor electronic expansion valve 51, the indoor side liquid pipe shut-off valve 49, the third shut-off valve 47, and the first shut-off device throttling element 45, and flows out from the first shut-off valve 43.

[0090] The liquid refrigerant flowing out from the first shut-off valve (10, 21, 32, 43) merges and flows out from the outdoor liquid pipe shut-off valve 8. After being throttled by the outdoor throttling element 7, it becomes a low-temperature, low-pressure refrigerant. The low-temperature, low-pressure refrigerant evaporates into a low-temperature, low-pressure gaseous refrigerant in the outdoor heat exchanger 6. The low-temperature, low-pressure gaseous refrigerant passes through the switching valve 4 and the gas-liquid separator 3 in sequence and enters the suction port of the compressor 1, thus completing the heating operation.

[0091] In one or more embodiments of this application, the air conditioning system further includes a processing device 60.

[0092] Figure 17 This is a schematic block diagram of the hardware configuration of the processing device 60. The processing device 60 includes components such as a processor 601, volatile memory 602, non-volatile memory 603, a display device 604, an operation device 605, a communication interface 606, and a drive device 607, which are interconnected via a bus 608. The processor can be a dedicated processor, a central processing unit, etc. The processor can access the storage unit to execute instructions or application programs stored in the storage unit to achieve related functions. The display device is used to display various information. The operation device is used to receive various operations. The drive device is a hardware terminal that interacts with the storage medium. In one or more embodiments of this application, the storage medium includes media such as CD-ROM, floppy disk, and optical-magnetic-optical disk that record information in an optical, electrical, or magnetic manner, as shown in Figure 609. The storage medium can also be a semiconductor memory such as ROM or flash memory that records information in a point-and-click manner, as shown in Figure 610.

[0093] The processing device 60 can be an outdoor controller in the outdoor unit 101 of the air conditioning system, or an indoor controller in the indoor unit, such as an on-board system based on an MCU.

[0094] The functions of the processing device 60 will be described below.

[0095] The processing device 60 is configured to: estimate the temperature change rate of the air-conditioned room where the indoor unit is located, and the degree of deviation of the air-conditioned room temperature from the target temperature; estimate the target refrigerant temperature matching the current load of the air-conditioned room based on the temperature change rate and the degree of deviation; and estimate the opening degree of the indoor electronic expansion valve, the throttling element of the first shut-off device, and the throttling element of the second shut-off device based on the target refrigerant temperature, the preset target superheat, or the target subcooling.

[0096] The air conditioning system provided in this application has multiple advantages in solving the problem of over-adjustment of indoor units under low-load conditions: First, through the throttling elements of the first and second cut-off devices in the refrigerant cut-off device, the air conditioning system can accurately adjust the refrigerant flow and temperature, avoiding temperature fluctuations caused by over-adjustment or under-adjustment; Second, by estimating the rate of temperature change and the degree of deviation from the target temperature in real time, the target refrigerant temperature is intelligently generated, ensuring that the control target matches the real-time load and avoiding user experience loss due to control delays and thermal inertia; In addition, the air conditioning system optimizes the adjustment according to the current load matching situation, improving energy utilization efficiency, thereby comprehensively optimizing the performance, comfort, and energy efficiency of the air conditioning system.

[0097] like Figure 1 and Figure 4 As shown, air-conditioned rooms (room 1, room 2, room 3, and room 4) are equipped with a first indoor unit, a second indoor unit, a third indoor unit, and a fourth indoor unit, respectively. These indoor units are connected to a first refrigerant shut-off device, a second refrigerant shut-off device, a third refrigerant shut-off device, and a fourth refrigerant shut-off device, respectively. An outdoor unit is installed outdoors and is connected via piping to the first refrigerant shut-off device, the second refrigerant shut-off device, the third refrigerant shut-off device, and the fourth refrigerant shut-off device, as well as to the first, second, third, and fourth indoor units, respectively.

[0098] In one or more embodiments of this application, only some indoor units may be equipped with refrigerant shut-off devices, meaning the number of refrigerant shut-off devices is less than the number of indoor units. Since the indoor units, refrigerant shut-off devices, and indoor units are all independently equipped with shut-off valves, they can be disassembled and installed independently as needed, which also facilitates later maintenance.

[0099] In one or more embodiments of this application, in cooling mode, the processing device 60 is configured to perform the following steps as shown in the figure when estimating the opening of the indoor electronic expansion valve, the first shut-off device throttling element, and the second shut-off device throttling element based on the target refrigerant temperature, a preset target superheat, or a target subcooling:

[0100] The throttling element of the first cut-off device is controlled to be at its maximum opening.

[0101] The real-time refrigerant temperature of the indoor heat exchanger is obtained, and the opening degree of the indoor electronic expansion valve is estimated based on the target refrigerant temperature and the real-time refrigerant temperature of the indoor heat exchanger.

[0102] The system acquires the real-time liquid pipe temperature and gas pipe temperature of the indoor heat exchanger, calculates the refrigerant superheat based on the liquid pipe temperature and the real-time gas pipe temperature, and estimates the opening degree of the throttling element of the second cut-off device based on the target superheat and the refrigerant superheat.

[0103] Specifically, in cooling mode, the temperature change curve of the air-conditioned room over time is as follows: Figure 5 As shown.

[0104] exist Figure 5 Chinese: T i (n) represents the temperature of the air-conditioned room at time n, which is also the air temperature inside the air-conditioned room; T i (n-1) represents the temperature of the air-conditioned room at time n-1; τ(n) represents the temperature of the air-conditioned room at time n; τ(n-1) represents the temperature of the air-conditioned room at time n-1; The rate of temperature change in an air-conditioned room; ΔT(n) = T i (n)-T s (n) represents the degree of deviation between the air-conditioned room temperature and the target temperature at time n; ΔT(n-1) = T i (n-1)-T s (n-1) represents the degree of deviation between the air-conditioned room temperature and the target temperature at time n-1; T s (n) represents the target temperature set by the user for the air-conditioned room at time n; T s (n-1) represents the target temperature set by the user at time n-1 in the air-conditioned room.

[0105] Furthermore, a data table can be constructed showing the rate of temperature change, degree of deviation, and target refrigerant temperature of the air-conditioned room. Figure 6 This is an example of a data table.

[0106] exist Figure 6 Among them, there are α1<α2<α3<α4<α5<...<α n ≤0℃, β1>β2>β3>β4>...>β n ≥0℃.

[0107] The rate of temperature change and the degree of deviation characterize the building load. In cooling mode, the target refrigerant temperature in the data table satisfies the following relationship: along each row of the data table, the target refrigerant temperature gradually decreases, and along each column of the data table, the target refrigerant temperature gradually increases. That is:

[0108] T eo_11 >T eo_21 >T eo_31 >T eo_41 >...>T eo_n1 ;

[0109] T eo_11 <T eo_12 <T eo_13 <T eo_14 <... <T eo_1n ;

[0110] T eo_1n >T eo_2n >T eo_3n >T eo_4n >...>T eo_nn .

[0111] In addition to data tables, a heat load model for an air-conditioned room can be established based on the rate of temperature change and the degree of deviation. The target refrigerant temperature can be predicted through the model. Alternatively, a heat load model can be established by training and learning historical data on the rate of temperature change and the degree of deviation using machine learning algorithms (such as neural networks, support vector machines, or decision trees). The target refrigerant temperature can also be calculated based on empirical formulas established using the rate of temperature change and the degree of deviation. Or, the target refrigerant temperature can be calculated using a polynomial fitting method under several known sets of temperature change rates and deviations.

[0112] In one or more embodiments of this application, the indoor heat exchanger is a finned tube heat exchanger, and the real-time refrigerant temperature of the indoor heat exchanger is detected by a coil temperature sensor 505 located at the intermediate coil position of the indoor heat exchanger. The real-time refrigerant temperature of the indoor heat exchanger is denoted as T. sat .

[0113] In one or more embodiments of this application,

[0114] The processing unit 60 is configured to perform the following steps when estimating the opening of the indoor electronic expansion valve based on the target refrigerant temperature and the real-time indoor heat exchanger refrigerant temperature:

[0115] When the target refrigerant temperature is higher than the real-time indoor heat exchanger refrigerant temperature, control is executed to reduce the opening of the indoor electronic expansion valve;

[0116] When the target refrigerant temperature is lower than the real-time indoor heat exchanger refrigerant temperature, control is executed to increase the opening of the indoor electronic expansion valve;

[0117] When the target refrigerant temperature equals the real-time indoor heat exchanger refrigerant temperature, control is executed to maintain the opening of the indoor electronic expansion valve.

[0118] In cooling mode, the target refrigerant temperature is denoted as Teo, that is:

[0119] T sat Teo controls the opening of the indoor electronic expansion valve to reduce the refrigerant temperature.

[0120] T sat <Teo performs the control of increasing the opening degree of the indoor electronic expansion valve to increase the refrigerant temperature.

[0121] T sat = Teo, performs the control of maintaining the opening degree of the indoor electronic expansion valve.

[0122] Taking Room 1 and Room 2 as examples, in the refrigeration mode, assuming the target set temperature T s (n) is 26 °C, and the initial temperatures in Room 1 and Room 2 at the 0th moment are both 35 °C. According to the relationship between ΔT(n), the refrigerant target temperatures T eo in Room 1 and Room 2 at the 1st moment, 2nd moment, 3rd moment, 4th moment, 5th moment, 6th moment, 7th moment, and 8th moment are 11.2 °C and 8.2 °C; 11.5 °C and 10.4 °C; 13.7 °C and 11.5 °C; 14.8 °C and 13.7 °C; 15.9 °C and 14.8 °C; 16.8 °C and 15.9 °C; 16.8 °C and 16.8 °C; 16.8 °C and 16.8 °C respectively. That is, the control of the opening degree of the indoor electronic expansion valve can be performed according to the above relationship between T sat and Teo.

[0123] The processing device 60 is configured to perform the following steps when estimating the opening degree of the throttling element of the second cut-off device based on the target superheat and the refrigerant superheat:

[0124] When the refrigerant superheat is higher than the target superheat, perform the control of increasing the opening degree of the throttling element of the second cut-off device;

[0125] When the refrigerant superheat is lower than the target superheat, perform the control of reducing the opening degree of the throttling element of the second cut-off device;

[0126] When the refrigerant superheat is equal to the target superheat, perform the control of maintaining the opening degree of the throttling element of the second cut-off device.

[0127] Among them, as Figure 7 shown, the refrigerant superheat is based on the real-time liquid pipe temperature of the indoor heat exchanger (detected by the liquid pipe temperature sensor 506, denoted as T l ) and the real-time gas pipe temperature of the indoor heat exchanger (detected by the gas pipe temperature sensor 507, denoted as T g ), and the refrigerant superheat is denoted as SH. There is SH = T g - T i . The target superheat is denoted as SHo. The target superheat SHo can be preset or calculated. The techniques for setting or calculating the target superheat SHo can adopt the techniques disclosed in the prior art, which is not the focus of the protection of this invention and will not be elaborated here.

[0128] That is:

[0129] When SH > SHo, execute the control to increase the opening degree of the throttling element of the second cutoff device;

[0130] When SH < SHo, execute the control to decrease the opening degree of the throttling element of the second cutoff device;

[0131] When SH = SHo, execute the control to maintain the opening degree of the throttling element of the second cutoff device.

[0132] Figure 8 This is an example of the refrigeration mode data table:

[0133] Figure 9 This is an example of the change in the target refrigerant temperature taking Rooms 1 and 2 as examples:

[0134] In one or more embodiments of the present application, in the heating mode, the processing device 60 is configured to execute the following steps when estimating the opening degrees of the indoor electronic expansion valve, the throttling element of the first cutoff device, and the throttling element of the second cutoff device based on the target refrigerant temperature, the preset target superheat degree, or the target subcooling degree:

[0135] Obtain the real-time refrigerant temperature of the indoor heat exchanger, and estimate the opening degree of the throttling element of the second cutoff device based on the target refrigerant temperature and the real-time refrigerant temperature of the heat exchanger;

[0136] Obtain the real-time liquid pipe temperature of the indoor heat exchanger, calculate the refrigerant subcooling degree based on the real-time liquid pipe temperature of the indoor heat exchanger and the real-time refrigerant temperature of the heat exchanger, and estimate the opening degree of the indoor electronic expansion valve based on the target subcooling degree and the refrigerant subcooling degree;

[0137] Control the throttling element of the first cutoff device to be at the maximum opening degree.

[0138] Specifically, in the heating mode, the curve of the temperature change in the air-conditioned room over time is as Figure 10 shown.

[0139] In Figure 10 , T i (n) is the temperature of the air-conditioned room at the nth moment, that is, the air temperature in the air-conditioned room; T i (n - 1) is the temperature of the air-conditioned room at the (n - 1)th moment; τ(n) is the nth moment in the air-conditioned room; τ(n - 1) is the (n - 1)th moment in the air-conditioned room; is the temperature change rate of the air-conditioned room; ΔT(n) = T i (n) - T s (n) is the degree of deviation of the temperature of the air-conditioned room at the nth moment from the target temperature; AT(n - 1) = T i (n - 1) - Ts (n-1) represents the degree of deviation between the air-conditioned room temperature and the target temperature at time n-1; T s (n) represents the target temperature set by the user for the air-conditioned room at time n; T s (n-1) represents the target temperature set by the user at time n-1 in the air-conditioned room.

[0140] Furthermore, a data table can be constructed showing the rate of temperature change, degree of deviation, and target refrigerant temperature of the air-conditioned room; Figure 11 This is an example of a data table.

[0141] exist Figure 11 Among them, there are γ1>γ2>γ3>γ4>γ5>...>γ n ≥0℃, η1>η2>η3>η4>...>η n ≥0℃.

[0142] The rate of temperature change and the degree of deviation characterize the building load. Under heating mode, the target refrigerant temperature in the data table satisfies the following relationship: along each row of the data table, the target refrigerant temperature gradually increases, and along each column of the data table, the target refrigerant temperature gradually decreases. That is:

[0143] T co_11 <T co_21 <T co_31 <T co_41 <... <T co_n1 ;

[0144] T co_11 >T co_12 >T co_13 >T co_14 >...>T co_1n ;

[0145] T co_1n <T co_2n <T co_3n <T co_4n <... <T co_nn .

[0146] In addition to data tables, a heat load model for an air-conditioned room can be established based on the rate of temperature change and the degree of deviation. The target refrigerant temperature can be predicted through the model. Alternatively, a heat load model can be established by training and learning historical data on the rate of temperature change and the degree of deviation using machine learning algorithms (such as neural networks, support vector machines, or decision trees). The target refrigerant temperature can also be calculated based on empirical formulas established using the rate of temperature change and the degree of deviation. Or, the target refrigerant temperature can be calculated using a polynomial fitting method under several known sets of temperature change rates and deviations.

[0147] In one or more embodiments of the present application,

[0148] The processing device 60 is configured to perform the following steps when estimating the opening degree of the throttling element of the second cut-off device based on the target refrigerant temperature and the real-time heat exchanger refrigerant temperature:

[0149] When the real-time indoor heat exchanger refrigerant temperature is higher than the target refrigerant temperature, perform control to reduce the opening degree of the throttling element of the second cut-off device;

[0150] When the real-time indoor heat exchanger refrigerant temperature is lower than the target refrigerant temperature, perform control to increase the opening degree of the throttling element of the second cut-off device;

[0151] When the real-time indoor heat exchanger refrigerant temperature is equal to the target refrigerant temperature, perform control to maintain the opening degree of the throttling element of the second cut-off device.

[0152] In the heating mode, the target refrigerant temperature is denoted as Tco, that is:

[0153] T sat > Tco, perform control to reduce the opening degree of the throttling element of the second cut-off device to lower the refrigerant temperature;

[0154] T sat < Tco, perform control to increase the opening degree of the throttling element of the second cut-off device to raise the refrigerant temperature;

[0155] T sat = Tco, perform control to maintain the opening degree of the throttling element of the second cut-off device.

[0156] Taking Room 1 and Room 2 as examples, in the heating mode, assuming the target set temperature T s (n) of the two rooms is 26 °C, and the initial temperatures in Room 1 and Room 2 at the 0th moment are both 15 °C. According to the relationship between ΔT(n), the refrigerant target temperatures T co of Room 1 and Room 2 at the 1st moment, 2nd moment, 3rd moment, 4th moment, 5th moment, 6th moment, 7th moment, 8th moment, 9th moment are 41.4 °C, 46.0 °C; 40.0, 44.7 °C; 38.2 °C, 41.2 °C; 36.9 °C, 38.8 °C; 35.6 °C, 36.4 °C; 34.3 °C, 35.6 °C; 33.2, 34.3 °C; 33.2, 33.2 °C; 33.2, 33.2 °C respectively. That is, the control of the opening degree of the indoor electronic expansion valve can be performed according to the relationship between the above T sat and Tco.

[0157] The processing device 60 is configured to perform the following steps when estimating the opening degree of the indoor electronic expansion valve based on the target supercooling degree and the refrigerant supercooling degree:

[0158] When the refrigerant subcooling degree is higher than the target subcooling degree, control is executed to increase the opening degree of the indoor electronic expansion valve;

[0159] When the refrigerant subcooling degree is lower than the target subcooling degree, control is executed to decrease the opening degree of the indoor electronic expansion valve;

[0160] When the refrigerant subcooling degree is equal to the target subcooling degree, control is executed to maintain the opening degree of the indoor electronic expansion valve.

[0161] Among them, as Figure 12 shown, the refrigerant subcooling degree is calculated based on the real-time refrigerant temperature of the indoor heat exchanger and the real-time liquid pipe temperature of the indoor heat exchanger. The refrigerant subcooling degree is denoted as SC, and there is SC = T sat -T l . The target subcooling degree is denoted as SCo, and the target subcooling degree SCo can be preset or calculated. Setting or calculating the target subcooling degree SCo can adopt the techniques disclosed in the prior art, which is not the focus of the protection of this invention and will not be elaborated here.

[0162] That is:

[0163] SC > SCo, execute the control to increase the opening degree of the indoor electronic expansion valve.

[0164] SC < SCo, execute the control to decrease the opening degree of the indoor electronic expansion valve.

[0165] SC = SCo, execute the control to maintain the opening degree of the indoor electronic expansion valve.

[0166] Figure 13 The following is an example of the heating mode data table:

[0167] Figure 14 The following is an example of the change in the target refrigerant temperature taking Room 1 and Room 2 as examples.

[0168] In one or more embodiments of the present application, the processing device 60 is further configured to, when the refrigerant concentration in the air-conditioned room exceeds the set threshold, close the first throttling element and the second throttling element of the refrigerant cutoff device corresponding to the indoor unit, as Figure 15 shown.

[0169] That is, the refrigerant cutoff device has two functions:

[0170] 1. If refrigerant leakage occurs in the indoor unit, the first throttling element and the second throttling element in the refrigerant cutoff device are closed to prevent refrigerant from leaking into the room.

[0171] 2. When the loads of different rooms are unbalanced, the refrigerant temperature is adjusted by the first and second throttling elements of the refrigerant cut-off device to match the load with the capacity of the indoor unit, thereby avoiding frequent start-stop of the indoor unit and fluctuations in room temperature.

[0172] Refrigerant leak sensors (such as NDIR sensors) need to be installed in air-conditioned rooms. Figure 16 As shown in Figures 501-504, the refrigerant leak sensor is communicatively connected to the indoor unit. When a refrigerant leak occurs in the indoor unit, the first and second throttling elements of the refrigerant shut-off device close, and an alarm sounds simultaneously.

[0173] In one or more embodiments of this application, taking a leak in the first indoor unit as an example, a refrigerant leak occurs in the first indoor unit, and the refrigerant concentration in room 1 exceeds a set threshold. The processing device 60 shuts off the first and second throttling elements of the refrigerant shut-off device corresponding to the first indoor unit, and activates a buzzer (e.g., Figure 16 An alarm will be triggered as shown in Figures 401-404.

[0174] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0175] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. Air conditioning system, including: The outdoor unit includes a compressor and an outdoor heat exchanger; and The indoor unit includes an indoor heat exchanger and an indoor electronic expansion valve; Its characteristic is that it further includes: A refrigerant shut-off device, connected to the outdoor unit via liquid piping and gas piping on the outdoor unit side, and connected to the indoor unit via liquid piping and gas piping on the indoor unit side; comprising: The first shut-off device throttling element is disposed between the liquid piping on the outdoor unit side and the liquid piping on the indoor unit side; and The second shut-off device throttling element is disposed between the outdoor unit-side gas piping and the indoor unit-side gas piping; as well as, The processing device, in cooling mode, is configured to: estimate the rate of temperature change of the air-conditioned room where the indoor unit is located, and the degree of deviation of the air-conditioned room temperature from the target temperature; estimate the target refrigerant temperature matching the current load of the air-conditioned room based on the rate of temperature change and the degree of deviation; and estimate the opening degree of the indoor electronic expansion valve, the throttling element of the first shut-off device, and the throttling element of the second shut-off device based on the target refrigerant temperature and a preset target superheat or target subcooling. The processing device performs the following steps when estimating the opening degree of the indoor electronic expansion valve, the first shut-off device throttling element, and the second shut-off device throttling element based on the target refrigerant temperature, a preset target superheat, or a target subcooling: The first shut-off device throttling element is controlled to be at its maximum opening; the real-time refrigerant temperature of the indoor heat exchanger is obtained, and the opening of the indoor electronic expansion valve is estimated based on the target refrigerant temperature and the real-time indoor heat exchanger refrigerant temperature; the real-time liquid pipe temperature and gas pipe temperature of the indoor heat exchanger are obtained, and the refrigerant superheat is calculated based on the liquid pipe temperature and the real-time indoor heat exchanger gas pipe temperature; the opening of the second shut-off device throttling element is estimated based on the target superheat and the refrigerant superheat.

2. The air conditioning system according to claim 1, characterized in that, The air conditioning system includes multiple indoor units; the number of refrigerant shut-off devices is less than the number of indoor units.

3. The air conditioning system according to claim 1, characterized in that, The processing device is configured to perform the following steps when estimating the opening of the indoor electronic expansion valve based on the target refrigerant temperature and the real-time indoor heat exchanger refrigerant temperature: When the target refrigerant temperature is higher than the real-time indoor heat exchanger refrigerant temperature, control is executed to reduce the opening of the indoor electronic expansion valve; When the target refrigerant temperature is lower than the real-time indoor heat exchanger refrigerant temperature, control is executed to increase the opening of the indoor electronic expansion valve; When the target refrigerant temperature is equal to the real-time indoor heat exchanger refrigerant temperature, control is performed to maintain the opening of the indoor electronic expansion valve.

4. The air conditioning system according to claim 3, characterized in that, The processing device is configured to perform the following steps when estimating the opening degree of the throttling element of the second shut-off device based on the target superheat and the refrigerant superheat: When the refrigerant superheat is higher than the target superheat, control is performed to increase the opening degree of the throttling element of the second shut-off device; When the refrigerant superheat is lower than the target superheat, control is performed to reduce the opening of the throttling element of the second shut-off device; When the refrigerant superheat is equal to the target superheat, control is performed to maintain the opening degree of the throttling element of the second shut-off device.

5. The air conditioning system according to claim 1 or 2, characterized in that, The processing device is configured to estimate the rate of temperature change of the air-conditioned room where the indoor unit is located, and the degree of deviation of the air-conditioned room temperature from the target temperature; based on the rate of temperature change, the degree of deviation, and a preset data table, it estimates the target refrigerant temperature that matches the current load of the air-conditioned room.

6. The air conditioning system according to claim 1 or 2, characterized in that, The processing device is further configured to shut down the first and second throttling elements of the refrigerant shut-off device in the refrigerant shut-off device corresponding to the indoor unit when the refrigerant concentration in the air-conditioned room exceeds a set threshold.

7. Air conditioning system, including: The outdoor unit includes a compressor and an outdoor heat exchanger; and The indoor unit includes an indoor heat exchanger and an indoor electronic expansion valve; Its characteristic is that it further includes: A refrigerant shut-off device, connected to the outdoor unit via liquid piping and gas piping on the outdoor unit side, and connected to the indoor unit via liquid piping and gas piping on the indoor unit side; comprising: The first shut-off device throttling element is disposed between the liquid piping on the outdoor unit side and the liquid piping on the indoor unit side; and The second shut-off device throttling element is disposed between the outdoor unit-side gas piping and the indoor unit-side gas piping; as well as, The processing device, in heating mode, is configured to: estimate the temperature change rate of the air-conditioned room where the indoor unit is located, and the degree of deviation of the air-conditioned room temperature from the target temperature; estimate the target refrigerant temperature matching the current load of the air-conditioned room based on the temperature change rate and the degree of deviation; and estimate the opening degree of the indoor electronic expansion valve, the throttling element of the first shut-off device, and the throttling element of the second shut-off device based on the target refrigerant temperature and a preset target superheat or target subcooling. When the processing device estimates the opening degree of the indoor electronic expansion valve, the first shut-off device throttling element, and the second shut-off device throttling element based on the target refrigerant temperature, a preset target superheat, or a target subcooling, it performs the following steps: acquiring the real-time indoor heat exchanger refrigerant temperature; estimating the opening degree of the second shut-off device throttling element based on the target refrigerant temperature and the real-time indoor heat exchanger refrigerant temperature; acquiring the real-time indoor heat exchanger liquid pipe temperature; calculating the refrigerant subcooling based on the real-time indoor heat exchanger liquid pipe temperature and the real-time indoor heat exchanger refrigerant temperature; estimating the opening degree of the indoor electronic expansion valve based on the target subcooling and the refrigerant subcooling; and controlling the first shut-off device throttling element to be at its maximum opening degree.

8. The air conditioning system according to claim 7, characterized in that, The air conditioning system includes multiple indoor units; the number of refrigerant shut-off devices is less than the number of indoor units.

9. The air conditioning system according to claim 7, characterized in that, The processing device is configured to perform the following steps when estimating the opening degree of the throttling element of the second shut-off device based on the target refrigerant temperature and the real-time indoor heat exchanger refrigerant temperature: When the real-time indoor heat exchanger refrigerant temperature is higher than the target refrigerant temperature, control is performed to reduce the opening degree of the throttling element of the second cut-off device; When the real-time indoor heat exchanger refrigerant temperature is lower than the target refrigerant temperature, control is executed to increase the opening degree of the throttling element of the second cut-off device; When the real-time indoor heat exchanger refrigerant temperature is equal to the target refrigerant temperature, control is performed to maintain the opening degree of the throttling element of the second cut-off device.

10. The air conditioning system according to claim 9, characterized in that, The processing device is configured to perform the following steps when estimating the opening of the indoor electronic expansion valve based on the target subcooling and the refrigerant subcooling: When the refrigerant subcooling degree is higher than the target subcooling degree, control is executed to increase the opening degree of the indoor electronic expansion valve; When the refrigerant subcooling is lower than the target subcooling, control is performed to reduce the opening of the indoor electronic expansion valve; When the refrigerant subcooling is equal to the target subcooling, control is performed to maintain the opening of the indoor electronic expansion valve.

11. The air conditioning system according to claim 7 or 8, characterized in that, The processing device is configured to estimate the rate of temperature change of the air-conditioned room where the indoor unit is located, and the degree of deviation of the air-conditioned room temperature from the target temperature; based on the rate of temperature change, the degree of deviation, and a preset data table, it estimates the target refrigerant temperature that matches the current load of the air-conditioned room.

12. The air conditioning system according to claim 7 or 8, characterized in that, The processing device is further configured to shut down the first and second throttling elements of the refrigerant shut-off device in the refrigerant shut-off device corresponding to the indoor unit when the refrigerant concentration in the air-conditioned room exceeds a set threshold.

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