Multi-split system

Abstract

The invention provides a multi-split air conditioner system. The multi-split air conditioner system comprises an outdoor refrigerant-air heat exchanger connected with a first outdoor throttling element; the refrigerant-water heat exchanger is connected with the second outdoor throttling element; a heat radiation indoor terminal; the integrated indoor terminal comprises a fresh air module used for forming fresh air; the regulating module comprises a first indoor refrigerant-air heat exchanger connected with the first indoor throttling element; the first fan is used for feeding fresh air; the processing device is configured in a heating mode and operably enables the first fan to continuously provide at least a preset minimum fresh air volume; real-time return air and air supply temperature of the integrated indoor terminal are sampled; and when the real-time air return temperature, the air supply temperature and / or the temperature difference between the real-time air return temperature and the real-time air supply temperature meet the preset intervention condition, the preset intervention opening degree is called, and the opening degree of the first outdoor throttling element and / or the second outdoor throttling element located in the throttling work interval is corrected. In the heating mode, temperature fluctuation caused by uninterrupted introduction of fresh air can be restrained.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigeration equipment, and in particular to a multi-connected system. Background Art

[0002] In the existing multi-split system, two different indoor units can be configured, one of which is the air-side indoor unit, which uses direct heat exchange between refrigerant and air to supply air, and the other is the water-side indoor unit, which is a radiation heating system (such as floor heating). The radiation heating system radiates heat through the floor, and the temperature distribution is more uniform, and the required heating temperature is lower. Therefore, giving priority to floor heating in winter can allow the multi-split system to operate under more efficient conditions and reduce energy consumption. However, the heating speed of floor heating is slow, and it takes 30-60 minutes to feel a significant effect; therefore, when rapid temperature increase is required, the two indoor units are usually used in combination, with the air-side indoor unit being started first and running at high wind speed and high power. Then the water-side indoor unit will play its radiation heating advantage and provide uniform heat distribution.

[0003] VRF systems require fresh air functionality, specifically requiring a 24-hour, uninterrupted supply of fresh air. The fresh air module is integrated into the indoor units on the air side. The 24-hour continuous introduction of cooler outdoor air can cause indoor temperature fluctuations, especially during rapid temperature rises. Because the VRF system's overall design capacity remains constant, and its limited heat output must simultaneously handle both indoor heating and fresh air preheating, the air supply temperature of the indoor units on the air side can be low, causing user discomfort. During the maintenance phase, when floor heating is the primary source of heat, fresh air can also disrupt temperature distribution, diminishing the uniform radiant heating benefits of the floor heating system.

[0004] The above information disclosed in this background technology is only used to increase the understanding of the background technology of this application. Therefore, it may contain information that does not constitute the prior art known to ordinary technicians in this field. Summary of the Invention

[0005] The first aspect of the present application provides a multi-split system. The multi-split system includes: an outdoor refrigerant-air heat exchanger connected to a first outdoor throttling element; a refrigerant-water heat exchanger connected to a second outdoor throttling element; a heat radiation indoor terminal, the refrigerant-water heat exchanger supplies water to the heat radiation indoor terminal; an integrated indoor terminal, which includes: a fresh air module, which is used to introduce outdoor air and mix and filter the outdoor air with the indoor return air to form fresh air; a regulating module, which includes: a first indoor refrigerant-air heat exchanger, which is configured to exchange heat between the refrigerant and the fresh air, and is connected to the first indoor throttling element; and a second indoor terminal. A fan for delivering heat-exchanged fresh air into the indoor space; a processing device, which is configured in a heating mode and is operable to enable the first fan to continuously provide at least a preset minimum amount of fresh air; sampling the real-time return air temperature and the real-time supply air temperature of the integrated indoor terminal; when the real-time return air temperature, the real-time supply air temperature, and / or the temperature difference between the real-time return air temperature and the real-time supply air temperature meets a preset intervention condition, calling a preset intervention opening and correcting the opening of the first indoor throttling element in the throttling working range and / or the second outdoor throttling element in the throttling working range.

[0006] The above technical solution has the following advantages or beneficial effects: the processing device allows independent and fine control of the integrated indoor terminal and the heat radiation indoor terminal by intervening in the opening. When fresh air is continuously introduced, the opening of the first indoor throttling element and the second outdoor throttling element is intervened to achieve rapid compensation of the system and avoid the problem of low supply air temperature; at the same time, it can also compensate for the cold and heat interference brought by the fresh air, so that the overall temperature distribution of the entire indoor environment is uniform.

[0007] In some embodiments of the present application, the processing device is configured to execute the following method to correct the opening of the first indoor throttling element in the throttling working interval: determine whether the real-time return air temperature meets the first real-time return air temperature intervention condition; determine whether the difference between the real-time return air temperature and the real-time return air temperature meets the first supply air temperature difference intervention condition; if the real-time return air temperature meets the first real-time return air temperature intervention condition, or the difference between the real-time supply air temperature and the real-time return air temperature meets the first supply air temperature difference intervention condition, then call the first intervention opening to increase the opening of the first indoor throttling element in the throttling working interval; otherwise, keep the opening of the first indoor throttling element in the throttling working interval unchanged.

[0008] The above technical solution has the following advantages or beneficial effects: through a dynamic adjustment mechanism based on temperature feedback, the first indoor throttling element in the air-conditioning system is optimized to compensate for the cold and hot interference that may be caused by the introduction of fresh air, ensuring uniform indoor temperature distribution and stable system energy efficiency.

[0009] In some embodiments of the present application, when the real-time return air temperature is not lower than the first preset intervention return air temperature, it is judged that the real-time return air temperature meets the first real-time return air temperature intervention condition; when the difference between the real-time supply air temperature and the real-time return air temperature is not lower than the first preset intervention temperature difference, it is judged that the difference between the real-time supply air temperature and the real-time return air temperature meets the first supply air temperature difference intervention condition.

[0010] The above technical solution has the following advantages or beneficial effects: When the real-time return air temperature is no higher than the first preset intervention return air temperature, it indicates that the indoor return air is at a relatively low temperature and the injection of cold fresh air is causing heat loss. The first intervention opening is called to increase the valve opening of the first indoor throttling element in the throttling operating range, thereby enhancing heating capacity. When the difference between the real-time supply air temperature and the real-time return air temperature is no higher than the first preset intervention temperature difference, it indicates that the heat exchange efficiency between the supply air and return air is low, and fresh air interference is causing heat unevenness and delaying system response. By calling the first intervention opening to increase the opening of the first indoor throttling element in the throttling operating range, the stability of the heat exchange process is enhanced.

[0011] In some embodiments of the present application, the processing device is configured to execute the following method to correct the opening of the first indoor throttling element in the throttling working interval: determine whether the real-time return air temperature meets the second real-time return air temperature intervention condition; determine whether the difference between the real-time supply air temperature and the real-time return air temperature meets the second supply air temperature difference intervention condition; if the real-time return air temperature meets the second real-time return air temperature intervention condition, and the difference between the real-time supply air temperature and the real-time return air temperature meets the second supply air temperature difference intervention condition, then call the second intervention opening to reduce the opening of the first indoor throttling element in the throttling working interval; otherwise, keep the opening of the first indoor throttling element in the throttling working interval unchanged.

[0012] The above technical solution has the following advantages or beneficial effects: through temperature feedback and condition judgment mechanism, the first indoor throttling element in the air-conditioning system is dynamically throttled to cope with the heat accumulation or temperature unevenness caused by the introduction of fresh air, ensuring that the air-conditioning system maintains stable indoor temperature under complex working conditions.

[0013] In some embodiments of the present application, when the real-time return air temperature is not higher than the first preset intervention return air temperature, it is judged that the real-time return air temperature meets the second real-time return air temperature intervention condition; when the difference between the real-time supply air temperature and the real-time return air temperature is not higher than the second preset intervention temperature difference, it is judged that the difference between the real-time supply air temperature and the real-time return air temperature meets the second supply air temperature difference intervention condition.

[0014] The above technical solution has the following advantages or beneficial effects: When the real-time return air temperature is not higher than the first preset intervention return air temperature, it indicates that the indoor return air is already at a high temperature and may be overheating. At this time, the second real-time return air temperature intervention condition is further determined to confirm the necessity of intervention. In other words, when the difference between the real-time supply air temperature and the real-time return air temperature is not higher than the second preset intervention temperature difference, it indicates that the heat exchange temperature difference between the supply air and the return air is large, and the possibility of excess heat is high. Once all conditions are met, the second intervention opening is called to reduce the valve opening, thereby appropriately reducing heating capacity in heating mode and avoiding heat waste caused by excessive temperatures.

[0015] The first indoor throttling element and the second outdoor throttling element are electronic expansion valves; the first intervention opening is a first basic value; the first basic value is the product of the upper limit opening of the electronic expansion valve and a predefined percentage; or the product of the opening calculated in the previous cycle and a predefined multiplier; the second intervention opening is a second basic value; the second basic value is the product of the upper limit opening of the electronic expansion valve and a predefined percentage; or the product of the opening calculated in the previous cycle and a predefined multiplier.

[0016] The above technical solution has the following advantages or beneficial effects: the first basic value and the second basic value can be set in a static upper limit ratio or a dynamic historical feedback, which avoids the rigidity problem that may be caused by the fixed value setting, and the opening degree increases or decreases gently during intervention, preventing the refrigerant flow from changing sharply due to the transition of the valve opening, and reducing temperature fluctuations; a smooth transition based on the operating status of the previous cycle helps to maintain system continuity, especially in scenarios with frequent fresh air interference, thereby improving adaptive capabilities.

[0017] In some embodiments of the present application, the first intervention opening is the sum of the first base value and the first correction value; wherein the first correction value is the first preset intervention temperature difference, and the ratio of the difference between the real-time supply air temperature and the real-time return air temperature; the second intervention opening is the sum of the second base value and the second correction value; wherein the second correction value is the difference between the real-time supply air temperature and the real-time return air temperature, and the ratio of the second preset intervention temperature difference.

[0018] The above technical solution has the following advantages or beneficial effects: through the first correction value and the second correction value, the opening degree changes faster and more significantly, thereby improving the responsiveness of the regulating valve and the multi-connected system corrects deviations more actively.

[0019] In some embodiments of the present application, the processing device is configured to execute the following method to correct the opening of the second outdoor throttling element in the throttling working interval: determine whether the real-time return air temperature meets the first real-time return air temperature intervention condition; determine whether the real-time supply air temperature meets the first real-time supply air temperature intervention condition; if the real-time return air temperature meets the first real-time return air temperature intervention condition, and the real-time supply air temperature meets the first real-time supply air temperature intervention condition, then drive the second outdoor throttling element in the throttling working interval to work at the capacity ratio corresponding opening; otherwise, keep the opening of the second outdoor throttling element in the throttling working interval unchanged; wherein, the capacity ratio corresponding opening is generated based on the ratio of the total capacity of the integrated indoor terminal currently in working state and the capacity of the outdoor unit; the larger the ratio of the total capacity of the integrated indoor terminal currently in working state and the capacity of the outdoor unit, the smaller the capacity ratio corresponding opening is.

[0020] The above technical solution has the following advantages or beneficial effects: This application uses a multi-condition judgment mechanism based on temperature thresholds to accurately intervene in the second outdoor throttling element to cope with the temperature deviation caused by the introduction of fresh air, thereby ensuring the indoor temperature stability and heat exchange efficiency under dynamic working conditions.

[0021] In some embodiments of the present application, the processing device is configured to execute the following method to correct the opening degree of the second outdoor throttling element in the throttling working range: determine whether the real-time return air temperature meets the second real-time return air temperature intervention condition and exceeds the preset duration, wherein the real-time return air temperature that meets the second real-time return air temperature intervention condition is higher than the real-time return air temperature that meets the first real-time return air temperature intervention condition; if the real-time return air temperature meets the second real-time return air temperature intervention condition and exceeds the preset duration, drive the second outdoor throttling element in the throttling working range to operate in the fully open working range.

[0022] The above technical solution has the following advantages or beneficial effects: when the return air temperature is high for a long time, the processing device allows the heat radiation indoor terminal to perform heating as a more stable heat source to ensure user comfort.

[0023] In some embodiments of the present application, the fresh air module includes a fresh air valve, and the processing device is configured to execute the following method to control the fresh air valve: sampling the real-time fresh air temperature; judging whether the real-time return air temperature meets the preset return air temperature working condition; judging whether the temperature difference between the real-time return air temperature and the real-time fresh air temperature meets the preset first fresh air temperature influencing condition; or, judging whether the real-time fresh air temperature meets the preset second fresh air temperature influencing condition; if the real-time return air temperature meets the preset return air temperature working condition and the temperature difference between the real-time return air temperature and the real-time fresh air temperature meets the preset first fresh air temperature influencing condition; or the real-time return air temperature meets the preset return air temperature working condition and the real-time fresh air temperature meets the preset second fresh air temperature influencing condition, then keep the fresh air valve at the working opening; otherwise, drive the fresh air valve to close.

[0024] The above technical solution has the following advantages or beneficial effects: The processing device first determines whether the return air temperature is within the preset return air temperature operating condition. Then, it evaluates whether the fresh air temperature difference or the real-time fresh air temperature meets the first fresh air temperature impact condition or the second fresh air temperature impact condition to measure the temperature disturbance caused by the fresh air. If the condition is met, the air valve is kept open to allow ventilation; otherwise, the air valve is closed to prevent temperature fluctuations caused by the cold and hot shock of the fresh air.

[0025] Other features and advantages of the present invention will become more apparent after reading the detailed description of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0027] Figure 1 A schematic diagram of the structure of a multi-connected system provided by some embodiments of the present invention;

[0028] Figure 2 A schematic diagram of the structure of a multi-connected system provided by some embodiments of the present invention;

[0029] Figure 3 A schematic diagram of the structure of an integrated indoor terminal in a multi-connected system provided by some embodiments of the present invention;

[0030] Figure 4 A schematic diagram of the structure of an integrated indoor terminal in a multi-connected system provided by some embodiments of the present invention;

[0031] Figure 5A schematic diagram of the structure of an integrated indoor terminal in a multi-connected system provided by some embodiments of the present invention;

[0032] Figure 6 A schematic diagram of the structure of an integrated indoor terminal in a multi-connected system provided by some embodiments of the present invention;

[0033] Figure 7 A flow chart of a multi-connection system provided by some embodiments of the present invention;

[0034] Figure 8 A flow chart of a multi-connection system provided by some embodiments of the present invention;

[0035] Figure 9 A flow chart of a multi-connection system provided by some embodiments of the present invention;

[0036] Figure 10 A flow chart of a multi-connection system provided by some embodiments of the present invention;

[0037] Figure 11 A flow chart of a multi-connection system provided by some embodiments of the present invention;

[0038] Figure 12 A schematic structural diagram of a multi-connected system provided in some other embodiments of the present invention;

[0039] Figure 13 A schematic structural diagram of a multi-connected system provided in some other embodiments of the present invention;

[0040] Figure 14 A schematic diagram of a refrigeration cycle in a multi-split system refrigeration mode provided in some other embodiments of the present invention;

[0041] Figure 15 A schematic diagram of a refrigeration cycle in a multi-split system refrigeration mode provided in some other embodiments of the present invention;

[0042] Figure 16 A schematic diagram of a refrigeration cycle in a multi-split system refrigeration mode provided in some other embodiments of the present invention;

[0043] In the picture:

[0044] 1. Multi-connection system;

[0045] 2. Outdoor unit; 10. Compressor; 11. First protection element; 12. Pressure sensor; 13. Second protection element; 14. Outdoor refrigerant-air heat exchanger; 141. Heat exchanger body; 142. Reheat exchange pipe; 15. First outdoor throttling element; 16. First switching valve; 17. Gas-liquid separator; 18. Refrigerant-water heat exchanger; 181. Heat exchange branch; 182. Water supply branch; 19. Expansion tank; 20. Circulating water pump; 21. Second outdoor throttling element; 22. First stop valve; 23. Second stop valve; 24. Second switching valve; 25. First valve element; 26. Second valve element.

[0046] 3. Heat radiation indoor terminal;

[0047] 4. Integrated indoor terminal; 41. Fresh air module; 42. Adjustment module; 401. Fresh air duct; 402. Fresh air inlet; 403. Fresh air valve; 404. Air mixing box; 405. Purification module; 411. Return air temperature sensor; 412. Real-time fresh air temperature sensor; 413. Supply air temperature sensor; 420. Housing; 421. First indoor fan; 422. First indoor refrigerant-air heat exchanger; 423. Supply air outlet; 424. Return air outlet; 43. First indoor throttling element;

[0048] 5. Processing device;

[0049] 6. Heat convection indoor terminal; 61. Second indoor refrigerant-air heat exchanger; 62. Second indoor throttling element. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0051] In the description of this application, 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 this application and simplifying the description, and do not indicate or imply 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 a limitation on this application.

[0052] The terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, features specified as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0053] In the description of this application, 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, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0054] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature therebetween. Moreover, a first feature being "above," "above," and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "below," "below," and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0055] The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numbers and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0056] like Figures 1 to 6 As shown, the present application designs and provides a multi-split system 1. Based on thermodynamic principles, the circulation system of a multi-split system includes an evaporator, a compressor, a condenser, and a throttling device connected in sequence. The circulation system involves a series of processes involving compression, condensation, expansion, and evaporation to cool or heat the indoor space.

[0057] Specifically, low-temperature, low-pressure refrigerant enters the compressor, which compresses it into high-temperature, high-pressure refrigerant gas and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, releasing heat into the surrounding environment through the condensation process.

[0058] The throttling device expands the high-temperature, high-pressure liquid refrigerant condensed in the condenser into a low-pressure liquid. The evaporator evaporates the refrigerant expanded in the throttling device and returns the low-temperature, low-pressure refrigerant gas to the compressor. The evaporator achieves cooling by utilizing the latent heat of evaporation to exchange heat with the material being cooled.

[0059] Figure 1 This is a schematic diagram of the circulation system of a multi-split system 1 provided in some embodiments of the present application, in which the compressor 10 is a core component. The compressor 10 is used to compress the refrigerant, compressing the refrigerant from a low-pressure state to a high-pressure state, so that the refrigerant can effectively transfer heat in the refrigeration cycle.

[0060] A first protection element 11 is provided on the exhaust side of the compressor 10. The first protection element 11 is used to detect the pressure on the exhaust side of the compressor 10. When the pressure exceeds a safety threshold, the circuit of the compressor 10 is automatically cut off to prevent the compressor 10 from being damaged due to overpressure.

[0061] A pressure sensor 12 is provided on the exhaust side of the compressor 10. The pressure sensor 12 monitors the pressure of the high-temperature, high-pressure refrigerant discharged from the compressor 10 in real time, providing pressure feedback to the compressor 10 and the throttling device, further accurately and dynamically adjusting the operating frequency or opening to improve energy efficiency.

[0062] A second protection element 13 is provided on the suction side of the compressor 10. This element is used to detect the pressure on the suction side of the compressor 10. When the pressure falls below a safety threshold, the circuit of the compressor 10 is automatically disconnected, preventing damage to the VRF system 1 or a decrease in efficiency due to low pressure.

[0063] The outdoor unit of the multi-split system 1 refers to a portion of the circulation system including the compressor 10 .

[0064] The outdoor unit of the multi-split system 1 further includes an outdoor refrigerant-air heat exchanger 14 .

[0065] The outdoor refrigerant-air heat exchanger 14 is used to exchange heat between the refrigerant and the air. Refrigerant flows through the outdoor refrigerant-air heat exchanger 14, and air flows across the surface of the outdoor refrigerant-air heat exchanger 14 via a fan or natural convection, achieving heat exchange. The outdoor refrigerant-air heat exchanger 14 includes a heat exchanger body 141 and a reheat exchange pipe 142. The reheat exchange pipe 142 is located below and connected to the heat exchanger body 141. The fan can be an axial flow fan, a crossflow fan, or other optional fan type, and is located near the outdoor refrigerant-air heat exchanger 14.

[0066] In some embodiments of the present application, the throttling device includes a first outdoor throttling element 15 . The first outdoor throttling element 15 is connected to the outdoor refrigerant-air heat exchanger 14 , specifically, to the reheat exchange pipe 142 .

[0067] The outdoor unit also includes a first switching valve 16. The first switching valve 16 is a valve that switches the flow direction of the refrigerant according to the operating mode of the multi-split system 1. In cooling mode, the discharge side of the compressor 10 is connected to the outdoor refrigerant-air heat exchanger 14 through the first switching valve 16 and other pipelines, thereby allowing the outdoor refrigerant-air heat exchanger 14 to function as a condenser. In heating mode, the suction side of the compressor 10 is connected to the outdoor refrigerant-air heat exchanger 14 through the first switching valve 16 and other pipelines, thereby allowing the outdoor refrigerant-air heat exchanger 14 to function as an evaporator. The first switching valve 16 can be a four-way valve, or it can be another valve element or combination of valve elements that can achieve the same function.

[0068] The outdoor unit also includes a gas-liquid separator 17. This is a shell-shaped component used to separate the refrigerant into gas and liquid. It is located on the suction side of the compressor 10. Using principles such as gravity settling and centrifugal separation, this separator allows droplets entrained in the gaseous refrigerant or bubbles suspended in the liquid refrigerant to separate and settle or coalesce due to density differences, effectively separating the gaseous and liquid refrigerants.

[0069] The outdoor unit further includes a refrigerant-water heat exchanger 18. The refrigerant-water heat exchanger 18 is used to perform heat exchange between the refrigerant and water, transfer the heat in the refrigerant to the water, and provide heating water to the heat radiation indoor terminal 3.

[0070] The refrigerant-water heat exchanger 18 includes a heat exchange branch 181 and a water supply branch 182. Refrigerant flows in the heat exchange branch 181, while water flows in the water supply branch 182. The water supply branch 182 is connected to the heat radiator indoor terminal 3 via an expansion tank 19 and a circulating water pump 20. The circulating water pump 20 drives the water to circulate between the water supply branch 182 and the heat radiator indoor terminal 3, while the expansion tank 19 buffers pressure fluctuations caused by thermal expansion of the water, maintaining pressure stability and preventing damage to the pipeline due to overpressure.

[0071] The throttling device further includes a second outdoor throttling element 21 . The second outdoor throttling element 21 is connected to the refrigerant-water heat exchanger 18 , specifically, to the heat exchange branch 181 .

[0072] The outdoor unit further includes a first stop valve 22 and a second stop valve 23 .

[0073] The structure and function of the indoor unit are described below. The indoor unit includes multiple indoor terminals. The indoor terminals are devices located in the indoor space and are used to transfer the heat or cooling provided by the multi-split system 1 to the indoor environment.

[0074] In some embodiments of the present application, the indoor terminal includes one or more heat radiation indoor terminals 3 , and the heat radiation indoor terminal 3 is connected to the refrigerant-water heat exchanger 18 .

[0075] In some embodiments of the present application, the heat radiation indoor terminal 3 is a pipe buried in the floor (commonly known as floor heating).

[0076] In other embodiments of the present application, the heat radiation indoor terminal 3 is a pipe buried in the wall or arranged close to the wall; or a combination of a pipe buried in the floor and a pipe buried in the wall or arranged close to the wall.

[0077] The refrigerant-water heat exchanger 18 supplies water to the indoor heat radiation terminal 3, which then flows into the terminal 3. This heat is evenly and gently dissipated into the room through radiation heat transfer. This heating method of the indoor heat radiation terminal 3 ensures a more uniform indoor temperature distribution and provides a comfortable user experience. The indoor heat radiation terminals 3 can be distributed in multiple rooms, and these distributed terminals 3 are connected via a manifold.

[0078] In some embodiments of the present application, the indoor terminal further includes one or more integrated indoor terminals 4 .

[0079] The integrated indoor terminal 4 includes a fresh air module 41 and a conditioning module 42 .

[0080] The fresh air module 41 can introduce outdoor air, mix the outdoor air with indoor return air, and filter it to form fresh air to solve the indoor air quality problem.

[0081] The fresh air module 41 includes a fresh air duct 401. The fresh air duct 401 includes a fresh air inlet 402, which is connected to the air inlet duct leading to the outside. A fresh air valve 403 is provided in the fresh air duct 401: when the fresh air valve 403 is open, outdoor air is allowed to enter the fresh air duct 401; when the fresh air valve 403 is closed, the outdoor air is completely blocked from entering the fresh air duct 401. The opening of the fresh air valve 403 can control the amount of fresh air entering the fresh air duct 401. The fresh air valve 403 is an adjustable electric valve that receives an analog signal and positions the valve at any opening between the minimum and maximum openings. The outdoor air in the fresh air duct 401 is mixed with part of the indoor return air in the indoor return air duct in the air mixing box 404, and then the temperature and humidity are adjusted together through the adjustment module 42 before being sent out.

[0082] In some embodiments of the present application, the mixed air in the air mixing box 404 first passes through the purification module 405 to form fresh air, and then is sent to the conditioning module 42. The purification module 405 is used to filter large particle pollutants such as dust, pollen, and catkins in the mixed air. The purification module 405 includes one of a primary filter, a medium efficiency filter, and a HEPA filter, or a combination of multiple ones. Exemplarily, the primary filter is a filter with an efficiency range of approximately 20% to 40% or 40% to 60%, such as synthetic fiber, wire mesh, etc.; the medium efficiency filter is a filter with an efficiency range of approximately 60%-85%, which can intercept smaller dust, mold spores, pet dander and some smoke particles, such as synthetic fiber; the HEPA filter is a filter that meets the HEPA standard and captures particles through a variety of physical mechanisms.

[0083] The conditioning module 42 includes a first indoor refrigerant-air heat exchanger 422 and a first indoor fan 421. The first indoor fan 421 drives fresh air through the first indoor refrigerant-air heat exchanger 422, forcing the refrigerant in the first indoor refrigerant-air heat exchanger 422 to exchange heat with the fresh air through forced convection, and then delivers the heat-exchanged fresh air into the indoor space. During cooling, the first indoor refrigerant-air heat exchanger 422 acts as an evaporator, absorbing heat; during heating, it acts as a condenser, releasing heat.

[0084] The integrated indoor terminal 4 includes a housing 420. Housing 420 provides structural support and protects internal components. On the indoor side, housing 420 features a return air vent 424 and a supply air vent 423. The return air vent 424 draws in indoor return air, while the supply air vent 423 delivers conditioned air into the indoor space. Both the return air vent 424 and the supply air vent 423 are equipped with removable grilles for easy maintenance and cleaning.

[0085] The throttling device also includes a first indoor throttling element 43. The first indoor throttling element 43 is connected to the first indoor refrigerant-air heat exchanger 422. When multiple integrated indoor terminals 4 are provided, multiple first indoor throttling elements 43 are provided. The first indoor throttling elements 43 are connected to the first indoor refrigerant-air heat exchanger 422 in a one-to-one correspondence.

[0086] In some embodiments of the present application, the first outdoor throttling element 15, the first indoor throttling element 43, and the second indoor throttling element 62 are electronic expansion valves. Hereinafter, the fully open operating range refers to the electronic expansion valve opening corresponding to when the refrigerant flow rate is close to the maximum allowable value; the fully closed operating range refers to the electronic expansion valve opening corresponding to when the refrigerant flow rate is close to the minimum allowable value. The opening of the electronic expansion valve operating in the throttling operating range is calculated and dynamically adjusted based on a fuzzy PID algorithm, for example, based on the evaporator outlet superheat, or can also be calculated based on other algorithms or empirical formulas. It is generally not less than 10% to 20% of the opening in the fully open operating range.

[0087] In some embodiments of the present application, the multi-connected system 1 further includes a processing device 5 .

[0088] In some embodiments of the present application, the processing device 520 may be an on-board system built based on a micro-control unit in an outdoor unit. In other embodiments of the present application, the processing device 520 may be an on-board system built based on a micro-control unit in an indoor unit. In other embodiments of the present application, some functions of the processing device 520 may be implemented by an on-board system built based on a micro-control unit in an outdoor unit, and another part of the functions may be implemented by an on-board system built based on a micro-control unit in an indoor unit. In other embodiments of the present application, some functions of the processing device 520 may be implemented by an edge processing device 5 (such as a centralized controller or gateway) and / or a cloud server, and another part of the functions may be implemented by an on-board system built based on a micro-control unit in an outdoor unit and / or an indoor unit.

[0089] The processing device 5 is configured to enable the multi-split system 1 to execute the cooling mode: drive the first switching valve 16 to switch the flow path between the exhaust side of the compressor 10 and the outdoor refrigerant-air heat exchanger 14, and the flow path between the suction side of the compressor 10 and the first indoor refrigerant-air heat exchanger 422; drive the first outdoor throttling element 15 and the first indoor throttling element 43 to be in the throttling working range, and drive the second outdoor throttling element 21 to be in the fully closed working range.

[0090] Thus, if Figure 1 and Figure 2As shown, in the cooling mode, the high-temperature and high-pressure refrigerant gas discharged from the compressor 10 enters the outdoor refrigerant-air heat exchanger 14 through the first switching valve 16, and is condensed in the outdoor refrigerant-air heat exchanger 14. The outdoor refrigerant-air heat exchanger 14 condenses the compressed refrigerant into a liquid phase; the refrigerant flowing out of the outdoor refrigerant-air heat exchanger 14 passes through the first outdoor throttling element 15, the first indoor throttling element 43, and the first indoor refrigerant-air heat exchanger 422 working as an evaporator in sequence; after flowing out of the first indoor refrigerant-air heat exchanger 422, it returns to the compressor 10 for the next cycle.

[0091] In some embodiments of the present application, the processing device 5 is configured to enable the multi-split system to execute a heating mode. During heating, the heat radiation indoor terminal 3 and the integrated indoor terminal 4 can work independently or in conjunction.

[0092] When heat radiation indoor terminal 3 operates independently, it drives first switching valve 16 to switch the flow path between the suction side of compressor 10 and outdoor refrigerant-air heat exchanger 14. Second outdoor throttle element 21 and first outdoor throttle element 15 are driven to the throttle operating range, while first indoor throttle element 43 is driven to the fully closed operating range. Refrigerant-water heat exchanger 18 operates as a condenser, and outdoor refrigerant-air heat exchanger 14 operates as an evaporator.

[0093] When the integrated indoor terminal 4 operates independently, it drives the first switching valve 16 to switch the flow path between the discharge side of the compressor 10 and the first indoor refrigerant-air heat exchanger 422, and the flow path between the suction side of the compressor 10 and the outdoor refrigerant-air heat exchanger 14. The first indoor throttle element 43 and the first outdoor throttle element 15 are driven into the throttling operating range, and the second outdoor throttle element 21 is driven into the fully closed operating range. The first indoor refrigerant-air heat exchanger 422 operates as a condenser, and the outdoor refrigerant-air heat exchanger 14 operates as an evaporator.

[0094] When the heat radiation indoor terminal 3 and the integrated indoor terminal 4 operate together, the first switching valve 16 is driven to switch the flow path between the discharge side of the compressor 10 and the first indoor refrigerant-air heat exchanger 422, and the flow path between the suction side of the compressor 10 and the outdoor refrigerant-air heat exchanger 14. The second outdoor throttling element 21, the first indoor throttling element 43, and the first outdoor throttling element 15 are driven into the throttling operating range. The refrigerant-water heat exchanger 18 and the first indoor refrigerant-air heat exchanger 422 both operate as condensers, and the outdoor refrigerant-air heat exchanger 14 operates as an evaporator.

[0095] Taking heating mode as an example, during the equipment selection and design phase of VRF system 1, the number of outdoor units (the capacity of VRF system 1) is determined based on the building's total heating load. Based on the total capacity of VRF system 1, the heating capacity is further allocated between the heat radiation indoor terminal 3 (including the refrigerant-water heat exchanger 18) and the integrated indoor terminal 4. If only the integrated indoor terminal 4 is used, the entire heating capacity of VRF system 1 is supplied to the integrated indoor terminal 4. If both the heat radiation indoor terminal 3 and the integrated indoor terminal 4 are used, since the heating capacity of VRF system 1 is fixed, the heating capacity of VRF system 1 is distributed between the integrated indoor terminal 4 and the heat radiation indoor terminal 3. The sum of the heating capacities allocated to both terminals is the total heating capacity of VRF system 1.

[0096] On the premise that the total heating capacity remains unchanged, the heating capacity is allocated to the integrated indoor terminal 4 and the heat radiation indoor terminal 3 at the same time, which means that the heating capacity allocated to the integrated indoor terminal 4 will not be higher than its maximum heating capacity when it operates alone; this makes the air supply temperature of the integrated indoor terminal 4 lower than when only the integrated indoor terminal 4 is operating, and the user will subjectively feel that the blown air is not hot enough.

[0097] During winter heating, thermal radiation indoor terminal 3 is prioritized. Integrated indoor terminal 4 is activated in two situations: first, during the initial startup of the multi-split system 1, to quickly raise the indoor temperature; and second, when the indoor temperature is too low, to quickly add a large amount of heat to meet the need for a higher temperature. Under this control strategy, integrated indoor terminal 4 and thermal radiation indoor terminal 3 operate simultaneously. Because user comfort is relatively low at this time, multi-split system 1 prioritizes the heating capacity of integrated indoor terminal 4, reducing the heat supply from thermal radiation indoor terminal 3 to prioritize maintaining the supply air temperature.

[0098] However, if the user also needs to continuously introduce fresh air (for example, for a full calendar day, i.e., 24 hours a day) to meet indoor air quality requirements, the integrated indoor terminal 4 needs to be continuously turned on. Due to outdoor air temperature fluctuations, in order to maintain a stable indoor temperature, the multi-split system 1 needs to rely on the thermal radiation indoor terminal 3 to bear the basic indoor heating load. At this time, the integrated indoor terminal 4 is used to process the fresh air load and provide the heat required to heat the outdoor air, or mixed air containing outdoor air, to a temperature close to the real-time indoor ambient temperature. The fresh air load is usually much smaller than the basic heating load of the room. The supply air temperature of the integrated indoor terminal 4 will not be higher than the supply air temperature during the traditional initial startup or compensation control. At the same time, since the thermal radiation indoor terminal 3 heats up slowly, the overall room temperature rises slowly, and cold air may be blown out, affecting the user's comfort.

[0099] To solve this problem, the processing device 5 is configured in the heating mode, and can be operated to enable the first fan to continuously provide at least a preset minimum amount of fresh air; sample the real-time return air temperature and the real-time supply air temperature of the integrated indoor terminal 4; when the real-time return air temperature, the real-time supply air temperature, and / or the temperature difference between the real-time return air temperature and the real-time supply air temperature meets the preset intervention condition, call the preset intervention opening, and correct the opening of the first indoor throttling element 43 in the throttling working range and / or the second outdoor throttling element 21 in the throttling working range to compensate for the temperature fluctuations in the indoor space.

[0100] Among them, the real-time return air temperature can be collected by the return air temperature sensor 411 set at the return air outlet 424, and the real-time supply air temperature can be collected by the supply air temperature sensor 413 set at the supply air outlet 423; the real-time fresh air temperature below can be collected by the real-time fresh air temperature sensor 412 set at the outlet of the mixing box 404.

[0101] The processing device 5 allows independent and fine control of the integrated indoor terminal 4 and the heat radiation indoor terminal 3 by intervening in the opening. When fresh air is continuously introduced, the system can be quickly compensated by intervening in the opening of the first indoor throttling element 43 and the second outdoor throttling element 21 to avoid the problem of low supply air temperature. At the same time, it can also compensate for the cold and hot interference brought by the fresh air, so that the overall temperature distribution of the entire indoor environment is uniform.

[0102] The processing device 5 is configured to execute the following method to correct the opening degree of the first indoor throttling element 43 in the throttling working range.

[0103] Determine whether the real-time return air temperature meets a first real-time return air temperature intervention condition.

[0104] Determine whether the difference between the real-time supply air temperature and the real-time return air temperature meets the first supply air temperature difference intervention condition.

[0105] If the real-time return air temperature satisfies the first real-time return air temperature intervention condition, or the difference between the real-time supply air temperature and the real-time return air temperature satisfies the first supply air temperature difference intervention condition, the first intervention opening is called to increase the opening of the first indoor throttling element 43 in the throttling working range. Otherwise, the opening of the first indoor throttling element 43 in the throttling working range is kept unchanged. Figure 7 As shown in steps S101 to S103.

[0106] Through a dynamic adjustment mechanism based on temperature feedback, the first indoor throttling element 43 in the multi-split system is optimized to compensate for the possible cold and hot interference caused by the introduction of fresh air, ensuring uniform indoor temperature distribution and stable system energy efficiency.

[0107] For example, when the real-time return air temperature is not higher than the first preset intervention return air temperature (real-time return air temperature ≤ first preset intervention return air temperature), it is determined that the real-time return air temperature meets the first real-time return air temperature intervention condition. The first preset intervention return air temperature is 20°C to 25°C.

[0108] When the real-time return air temperature is not higher than the first preset intervention return air temperature, the surface indoor return air is at a relatively low temperature state, and the injection of cold air from the fresh air causes heat loss. The first intervention opening is called to increase the opening valve opening of the first indoor throttling element 43 in the throttling working range, thereby enhancing the heating capacity.

[0109] For example, when the difference between the real-time supply air temperature and the real-time return air temperature is not greater than a first preset intervention temperature difference (real-time supply air temperature - real-time return air temperature ≤ first preset intervention temperature difference), the difference between the real-time supply air temperature and the real-time return air temperature is determined to meet the first supply air temperature difference intervention condition. The first preset intervention temperature difference is 0°C to 5°C.

[0110] When the difference between the real-time supply air temperature and the real-time return air temperature is not higher than the first preset intervention temperature difference, it indicates that the heat exchange efficiency between the supply air and the return air is not high, the fresh air interference causes uneven heat, and delays the system response. By calling the first intervention, the opening of the first indoor throttling element 43 in the throttling working range is increased to enhance the stability of the heat exchange process.

[0111] The processing device 5 is further configured to execute the following control method to correct the opening degree of the first indoor throttling element 43 in the throttling working range.

[0112] Determine whether the real-time return air temperature meets the second real-time return air temperature intervention condition.

[0113] Determine whether the difference between the real-time supply air temperature and the real-time return air temperature meets the second supply air temperature difference intervention condition.

[0114] If the real-time return air temperature satisfies the second real-time return air temperature intervention condition, and the difference between the real-time supply air temperature and the real-time return air temperature satisfies the second supply air temperature difference intervention condition, the second intervention opening is called to reduce the opening of the first indoor throttling element 43 in the throttling working range. Otherwise, the opening of the first indoor throttling element 43 in the throttling working range is kept unchanged. Figure 8 As shown in steps S201 to S203.

[0115] Through temperature feedback and condition judgment mechanism, the first indoor throttling element 43 in the multi-split system is dynamically throttled to cope with the heat accumulation or temperature unevenness that may be caused by the introduction of fresh air, ensuring that the multi-split system maintains stable indoor temperature under complex working conditions.

[0116] For example, when the real-time return air temperature is not lower than the first preset intervention return air temperature (the real-time return air temperature is greater than or equal to the first preset intervention return air temperature), it is determined that the real-time return air temperature meets the second real-time return air temperature intervention condition. The first preset intervention return air temperature is 20℃ to 25℃

[0117] For example, when the difference between the real-time supply air temperature and the real-time return air temperature is not less than a second preset intervention temperature difference (real-time supply air temperature - real-time return air temperature ≥ second preset intervention temperature difference), the difference between the real-time supply air temperature and the real-time return air temperature is determined to meet the second supply air temperature difference intervention condition. The second preset intervention temperature difference is 7°C to 15°C.

[0118] If the real-time return air temperature is not lower than the first preset intervention return air temperature, it indicates that the indoor return air is already at a high temperature, potentially causing overheating. The system then further determines whether the second real-time return air temperature intervention condition is met to confirm the necessity of intervention. Specifically, if the difference between the real-time supply air temperature and the real-time return air temperature is not lower than the second preset intervention temperature difference, it indicates a large heat exchange temperature difference between the supply and return air, increasing the likelihood of excess heat. Once all conditions are met, the second intervention opening is invoked to reduce the valve opening, thereby moderately reducing heating capacity in heating mode and preventing heat waste caused by excessive temperatures.

[0119] In some embodiments of the present application, the first intervention opening degree is a first basic value.

[0120] In some embodiments of the present application, the first basic value is the product of the upper limit opening of the electronic expansion valve and a predefined percentage, wherein the predefined percentage is within a predefined percentage interval; for example, the predefined percentage interval is 2% to 8%.

[0121] In some embodiments of the present application, the first base value is the product of the opening calculated in the previous period and a predefined multiplier, wherein the predefined multiplier is within a predefined multiplier range; for example, the predefined multiplier range is 0.25 to 0.5.

[0122] In some embodiments of the present application, the first intervention opening degree is the sum of a base value and a first correction value.

[0123] The calculation method of the first basic value is as described above and will not be repeated here. The first correction value is calculated based on the temperature difference.

[0124] Exemplarily, the first correction value is equal to the ratio of the first preset intervention temperature difference and the difference between the real-time supply air temperature and the real-time return air temperature.

[0125] In some embodiments of the present application, the second intervention opening degree is a second base value.

[0126] In some embodiments of the present application, the second basic value is the product of the upper limit opening of the electronic expansion valve and a predefined percentage, wherein the predefined percentage is within a predefined percentage interval; for example, the predefined percentage interval is 2% to 8%.

[0127] In some embodiments of the present application, the second base value is the product of the opening calculated in the previous period and a predefined multiplier, wherein the predefined multiplier is within a predefined multiplier range; for example, the predefined multiplier range is 0.25 to 0.5.

[0128] In some embodiments of the present application, the second intervention opening degree is the sum of the second base value and the second correction value.

[0129] The calculation method of the second basic value is as described above and will not be repeated here. The second correction value is calculated based on the temperature difference.

[0130] Exemplarily, the second correction value is equal to the ratio of the difference between the real-time supply air temperature and the real-time return air temperature to the second preset intervention temperature difference.

[0131] The first basic value and the second basic value can be set by selecting either a static upper limit ratio or a dynamic historical feedback. On the one hand, this avoids the rigidity problem that may be caused by setting a fixed value, and the opening degree increases or decreases gently during intervention, preventing a sharp change in refrigerant flow due to excessive opening of the valve, thereby reducing temperature fluctuations; a smooth transition based on the operating status of the previous cycle helps maintain system continuity, especially in scenarios with frequent fresh air interference, thereby improving adaptive capabilities.

[0132] If the difference between the real-time supply air temperature and the real-time return air temperature is large, the correction value will be larger, and the first intervention opening and the second intervention opening will also increase, so that the opening of the first throttling element changes faster and more significantly, thereby improving the responsiveness of the regulating valve, and the multi-connected system 1 corrects the deviation more actively.

[0133] The processing device 5 is further configured to execute the following method to correct the opening degree of the second outdoor throttling element 21 in the throttling working range.

[0134] Determine whether the real-time return air temperature meets a first real-time return air temperature intervention condition.

[0135] Determine whether the real-time supply air temperature meets a first real-time supply air temperature intervention condition.

[0136] For example, when the real-time return air temperature is not higher than a first preset intervention return air temperature (real-time return air temperature ≤ first preset intervention return air temperature), the real-time return air temperature is determined to meet the first real-time return air temperature intervention condition. The first preset intervention return air temperature is 20° C. to 25° C. The real-time return air temperature may be the minimum value of the real-time return air temperature within the sampling period.

[0137] For example, when the real-time supply air temperature is not higher than the preset intervention supply air temperature (real-time supply air temperature ≤ preset intervention supply air temperature), it is determined that the real-time supply air temperature meets the first real-time supply air temperature intervention condition. The preset intervention supply air temperature is 35°C to 38°C.

[0138] When the real-time return air temperature is not higher than the first preset intervention return air temperature, it means that the indoor return air is already at a lower temperature due to cold air interference. Further check whether the supply air temperature meets the first real-time supply air temperature intervention condition to detect whether there is a heat shortage problem in the system.

[0139] If the real-time return air temperature satisfies the first real-time return air temperature intervention condition, and the real-time supply air temperature satisfies the first real-time supply air temperature intervention condition, the second outdoor throttling element 21 in the throttling working range is driven to operate at an opening corresponding to the capacity ratio; otherwise, the opening of the second outdoor throttling element 21 in the throttling working range is kept unchanged. Figure 9 As shown in steps S301 to S303.

[0140] This application uses a multi-condition judgment mechanism based on temperature thresholds to accurately intervene in the second outdoor throttling element 21 to cope with the temperature deviation caused by the introduction of fresh air, ensuring the indoor temperature stability and heat exchange efficiency under dynamic working conditions.

[0141] The capacity ratio corresponding opening is generated based on the ratio of the total capacity of the currently operating integrated indoor terminals 4 to the capacity of the outdoor unit. The larger the ratio of the total capacity of the currently operating integrated indoor terminals 4 to the capacity of the outdoor unit, the smaller the capacity ratio corresponding opening.

[0142] Specifically, capacity refers to the heating capacity provided by the integrated indoor terminal 4 per unit time and can be obtained in real time. Outdoor unit capacity refers to the rated capacity of the outdoor unit in the multi-split system 1, that is, the maximum heating capacity the outdoor unit can provide under design conditions. This is a fixed value defined by the equipment specifications and can be directly accessed. The ratio of the total capacity of the currently operating integrated indoor terminals 4 to the outdoor unit capacity quantifies the proportion of the multi-split system 1 load relative to the outdoor unit capacity. There is a positive correlation between the capacity ratio and the corresponding opening degree. As the capacity ratio increases, the corresponding opening degree decreases.

[0143] The capacity ratio corresponding to the opening degree can be obtained by looking up in a predefined mapping table according to the capacity ratio.

[0144] For example, the mapping table shows the following: when the capacity ratio is not less than the first preset capacity ratio, the first capacity ratio corresponding to the opening is generated; when the capacity ratio is not less than the second preset capacity ratio but less than the first preset capacity ratio, the second capacity ratio corresponding to the opening is generated; when the capacity ratio is less than the second preset capacity ratio, the third capacity ratio corresponding to the opening is generated. If the first preset capacity ratio is in the range of 40% to 60%, for example, 50%, the first capacity ratio corresponds to an opening of 10%-20% of the maximum opening, for example, 15%; if the second preset capacity ratio is in the range of 20% to 40%, for example, 30%, the second capacity ratio corresponds to an opening of 20%-30% of the maximum opening, for example, 25%; and the third capacity ratio corresponds to an opening of 30%-40% of the maximum opening, for example, 35%. For example, if the capacity ratio is ≥50%, the first capacity ratio corresponds to an opening of 15% of the maximum opening; if the capacity ratio is 50%> or ≥30%, the second capacity ratio corresponds to an opening of 25% of the maximum opening; if the capacity ratio is <30%, the third capacity ratio corresponds to an opening of 35% of the maximum opening.

[0145] The processing device 5 is further configured to execute the following method to correct the opening degree of the second outdoor throttling element 21 in the throttling working range.

[0146] Determine whether the real-time return air temperature meets the second real-time return air temperature intervention condition.

[0147] For example, when the real-time return air temperature is higher than the first preset intervention return air temperature (the real-time return air temperature is greater than the first preset intervention return air temperature) and exceeds a preset duration, the real-time return air temperature is determined to meet the second real-time return air temperature intervention condition. The second preset intervention return air temperature is 20°C to 25°C, and the preset duration is 5-20 minutes.

[0148] If the real-time return air temperature meets the second real-time return air temperature intervention condition, the second outdoor throttling element 21 in the throttling working range is driven to work in the fully open working range. Otherwise, the opening degree of the second outdoor throttling element 21 in the throttling working range remains unchanged. Figure 10 As shown in steps S401 to S403.

[0149] When the return air temperature is high for a long time, the processing device 5 allows the heat radiation indoor terminal 3 to perform heating as a more stable heat source, ensuring user comfort and overall energy efficiency of the unit.

[0150] The processing device 5 is configured to execute the following method to control the fresh air valve 403:

[0151] Sampling real-time fresh air temperature;

[0152] Determine whether the real-time return air temperature meets the preset return air temperature working conditions;

[0153] Determine whether the temperature difference between the real-time return air temperature and the real-time fresh air temperature satisfies a preset first fresh air temperature influencing condition; or determine whether the real-time fresh air temperature satisfies a preset second fresh air temperature influencing condition;

[0154] If the real-time return air temperature meets the preset return air temperature working condition and the temperature difference between the real-time return air temperature and the real-time fresh air temperature meets the preset first fresh air temperature influencing condition; or the real-time return air temperature meets the preset return air temperature working condition and the real-time fresh air temperature meets the preset second fresh air temperature influencing condition, then keep the fresh air valve 403 at the working opening; otherwise, drive the fresh air valve 403 to close.

[0155] Processing device 5 first determines whether the return air temperature is within the preset return air temperature operating condition. It then evaluates whether the fresh air temperature difference or the real-time fresh air temperature meets a specific first fresh air temperature influencing condition or a second fresh air temperature influencing condition to measure the temperature disturbance caused by the fresh air. If the conditions are met, the damper is kept open to allow ventilation; otherwise, the damper is closed to prevent temperature fluctuations caused by the cold and hot shocks of the fresh air.

[0156] Specifically, if Figure 11 As shown,

[0157] Step S501: drive the first indoor fan 421 to operate, continuously provide at least a preset minimum amount of fresh air, and the fresh air valve 403 is at a working opening.

[0158] Step S502: Determine whether the operating time of the first indoor fan 421 meets the preset cycle working conditions.

[0159] Step S503: If the operating time of the first indoor fan 421 meets the preset cycle working conditions, the real-time return air temperature and the real-time fresh air temperature are sampled.

[0160] If the operation time of the first indoor fan 421 does not meet the preset cycle working condition, the first indoor fan 421 is kept running until the preset cycle working condition is met.

[0161] For example, when the operating time of the first indoor fan 421 is not longer than a preset operating time, it is determined that the operating time of the first indoor fan 421 meets the preset cycle working condition. The preset operating time is 5 seconds to 15 seconds.

[0162] Step S504: Determine whether the real-time return air temperature meets the preset return air temperature working condition.

[0163] For example, when the real-time return air temperature is not lower than the preset return air temperature (real-time return air temperature ≥ preset return air temperature), it is determined that the real-time return air temperature meets the preset return air temperature working condition. The preset return air temperature is 15°C to 20°C.

[0164] Step S505: Determine whether the temperature difference between the real-time return air temperature and the real-time fresh air temperature satisfies a preset first fresh air temperature influencing condition.

[0165] For example, if the difference between the real-time return air temperature and the real-time fresh air temperature is no greater than a preset temperature difference (real-time return air temperature - real-time fresh air temperature ≤ preset temperature difference), the difference between the real-time return air temperature and the real-time fresh air temperature is determined to satisfy a preset first fresh air temperature impact condition. The preset temperature difference is 3°C to 5°C. The difference between the real-time return air temperature and the real-time fresh air temperature can measure the impact factor of the real-time fresh air temperature on the real-time indoor ambient temperature.

[0166] Step S506: Determine whether the real-time fresh air temperature satisfies a preset second fresh air temperature influencing condition.

[0167] For example, when the real-time fresh air temperature is not lower than the preset fresh air temperature (real-time fresh air temperature ≥ preset fresh air temperature), it is determined that the real-time fresh air temperature meets the preset second fresh air temperature influencing condition. The preset fresh air temperature is 12°C to 15°C.

[0168] The determination of the second fresh air temperature influencing condition is used to reduce the probability of intervention control, so that when the impact factor of the real-time fresh air temperature on the real-time indoor ambient temperature is high, but the real-time fresh air temperature is still within an acceptable range, the fresh air is maintained in uninterrupted operation.

[0169] Step S507: If the real-time return air temperature satisfies the preset return air temperature working condition and the temperature difference between the real-time return air temperature and the real-time fresh air temperature satisfies the preset first fresh air temperature influencing condition;

[0170] Alternatively, in step S508, if the real-time return air temperature satisfies the preset return air temperature working condition and the real-time fresh air temperature satisfies the preset second fresh air temperature influencing condition, the fresh air valve 403 is kept at the working opening, step S509. Otherwise, the fresh air valve 403 is driven to close, step S510.

[0171] Step S511: After driving the fresh air valve 403 to close, determine whether the continuous operation time meets the preset fresh air recovery condition.

[0172] For example, when the continuous operation time is not greater than a preset continuous operation time, it is determined that the continuous operation time satisfies the preset fresh air restoration condition. The preset continuous operation time is a constant, pre-configured, and can be called at any time.

[0173] Step S512: If the continuous operation time meets the preset fresh air recovery condition, the fresh air valve 403 is driven to open and be at the working opening.

[0174] like Figures 12 to 16As shown, in other embodiments of the present application, one or more heat convection indoor terminals 6 are further provided in the indoor unit.

[0175] In some embodiments of the present application, the thermal convection indoor terminal 6 includes a second indoor refrigerant-air heat exchanger 61 and a second fan (not shown); the second fan drives the air to flow through the second indoor refrigerant-air heat exchanger 61, so that the refrigerant in the second indoor refrigerant-air heat exchanger 61 and the air are forced to exchange heat by convection. Forced convection can increase the fluid velocity, actively destroy the thermal boundary layer, reduce the thickness of the boundary layer, enhance fluid disturbance, and enhance the efficiency of heat transfer to the fluid. The thermal convection indoor terminal 6 can be used for normal cooling, normal heating, rapid cooling, or rapid heating. The second indoor refrigerant-air heat exchanger 61 is connected to the compressor 10 via the first switching valve 16.

[0176] The throttling device further includes a second indoor throttling element 62. The second indoor throttling element 62 is connected to the second indoor refrigerant-air heat exchanger 61.

[0177] In some embodiments of the present application, when multiple heat convection indoor terminals 6 are provided, multiple second indoor throttling elements 62 are correspondingly configured. The second indoor throttling elements 62 are connected to the second indoor refrigerant-air heat exchangers 61 in a one-to-one correspondence.

[0178] The outdoor unit also includes a second switching valve 24. This second switching valve 24 can connect the refrigerant-water heat exchanger 18, which operates as a condenser, to the first indoor refrigerant-air heat exchanger 422, which operates as a condenser; or it can connect the exhaust port of the compressor 10 to the first indoor refrigerant-air heat exchanger 422, which operates as a condenser. The second switching valve 24 is a four-way valve, and only three of its ports are used.

[0179] Through the design of the second switching valve, the refrigerant-water heat exchanger working as a condenser and the first indoor refrigerant-air heat exchanger working as a condenser can be connected, so that the temperature disturbance caused by the uninterrupted introduction of fresh air can be treated by utilizing the waste heat of the refrigerant-water heat exchanger.

[0180] The outdoor unit also includes a first valve element 25 and a second valve element 26. The first valve element 25 is used to operably guide the flow path between the refrigerant-water heat exchanger 18 and the second switching valve 24; the second valve element 26 is used to switch on or off the passage between the second switching valve 24 and the first indoor refrigerant-air heat exchanger 422.

[0181] By designing the first valve element 25 and the second valve element 26 , flexible management and optimization of the refrigerant flow path are achieved.

[0182] In some embodiments of the present application, the processing device 5 is configured to enable the multi-split system to perform a cooling mode: drive the first switching valve 16 and the second switching valve 24 to switch the flow path between the exhaust side of the compressor 10 and the outdoor refrigerant-air heat exchanger 14, the flow path between the suction side of the compressor 10 and the first indoor refrigerant-air heat exchanger 422, and the flow path between the suction side of the compressor 10 and the second indoor refrigerant-air heat exchanger 61; drive the first outdoor throttling element 15, the first indoor throttling element 43 and the second indoor throttling element 62 to be in the throttling working range, and drive the second outdoor throttling element 21 to be in the fully closed working range; the outdoor refrigerant-air heat exchanger 14 works as a condenser; the first indoor refrigerant-air heat exchanger 422 and the second indoor refrigerant-air heat exchanger 61 work as evaporators.

[0183] Thus, if Figure 14 As shown, in the cooling mode, the high-temperature and high-pressure refrigerant gas discharged from the compressor 10 enters the outdoor refrigerant-air heat exchanger 14 through the first switching valve 16, where it condenses and converts the compressed refrigerant into a liquid phase. The refrigerant flowing out of the outdoor refrigerant-air heat exchanger 14 passes through the first outdoor throttling element 15 in the throttling operating range, the first indoor throttling element 43, and the first indoor refrigerant-air heat exchanger 422 functioning as an evaporator. The refrigerant flows out of the first indoor refrigerant-air heat exchanger 422, passes through the second switching valve 24 and the first switching valve 16, and returns to the compressor 10. The refrigerant flows out of the second indoor refrigerant-air heat exchanger 61, passes through the first switching valve 16, and returns to the compressor 10 to begin the next cycle.

[0184] In some embodiments of the present application, the processing device 5 is configured to enable the multi-split system to perform a first heating mode: drive the first switching valve 16 to switch the flow path between the exhaust side of the compressor 10 and the second indoor refrigerant-air heat exchanger 61, and the flow path between the suction side of the compressor 10 and the outdoor refrigerant-air heat exchanger 14; drive the second switching valve 24 and the first valve element 25 to guide the formation of the flow path between the refrigerant-water heat exchanger 18 and the first indoor refrigerant-air heat exchanger 422; drive the first outdoor throttling element 15 to be in the throttling working range, the second outdoor throttling element 21 to be in the fully open working range, the first indoor throttling element 43 to be in the throttling working range, and the second indoor throttling element 62 to be in the throttling working range; the refrigerant-water heat exchanger 18, the first indoor refrigerant-air heat exchanger 422, and the second indoor refrigerant-air heat exchanger 61 work as condensers, and the outdoor refrigerant-air heat exchanger 14 works as an evaporator.

[0185] Thus, if Figure 15 As shown, in the first heating mode, the high-temperature and high-pressure refrigerant gas discharged from the compressor 10 enters the second indoor refrigerant-air heat exchanger 61 through the first switching valve 16, and is condensed in the second indoor refrigerant-air heat exchanger 61. The second indoor refrigerant-air heat exchanger 61 condenses the compressed refrigerant into a liquid phase; the refrigerant flowing out of the second indoor refrigerant-air heat exchanger 61 passes through the second indoor throttling element 62 in the throttling working range; the high-temperature and high-pressure refrigerant gas discharged from the compressor 10 enters the refrigerant-water heat exchanger 18 through the other path, and is condensed in the refrigerant-water heat exchanger 18; the refrigerant-water heat exchanger 18 condenses the compressed refrigerant into a liquid phase; the refrigerant flowing out of the refrigerant-water heat exchanger 18 The refrigerant passes through the second outdoor throttling element 21 in the fully open working range, and under the guidance of the first valve element 25 in the closed state, passes through the second switching valve 24 and enters the first indoor refrigerant-air heat exchanger 422; it is secondary condensed in the first indoor refrigerant-air heat exchanger 422, and the liquid refrigerant after secondary condensation passes through the first indoor throttling element 43 in the throttling working range; after merging the refrigerant passing through the first indoor throttling element 43 and the second indoor throttling element 62, it passes through the first outdoor throttling element 15 in the throttling working range and the outdoor refrigerant-air heat exchanger 14 working as an evaporator, flows out of the outdoor refrigerant-air heat exchanger 14 and returns to the compressor 10 through the first switching valve 16.

[0186] In some embodiments of the present application, the processing device 5 is configured to enable the multi-split system to perform a second heating mode: drive the first switching valve 16 and the second switching valve 24 to switch the flow path between the exhaust side of the compressor 10 and the first indoor refrigerant-air heat exchanger 422, the flow path between the exhaust side of the compressor 10 and the second indoor refrigerant-air heat exchanger 61, and the flow path between the suction side of the compressor 10 and the outdoor refrigerant-air heat exchanger 14; drive the first valve element 25 to switch the flow path between the refrigerant-water heat exchanger 18 and the outdoor refrigerant-air heat exchanger 14; drive the first outdoor throttling element 15 to be in the throttling working range, the second outdoor throttling element 21 to be in the throttling working range, the first indoor throttling element 43 to be in the throttling working range, and the second indoor throttling element 62 to be in the throttling working range; the refrigerant-water heat exchanger 18, the first indoor refrigerant-air heat exchanger 422, and the second indoor refrigerant-air heat exchanger 61 to work as condensers, and the outdoor refrigerant-air heat exchanger 14 to work as an evaporator.

[0187] Thus, if Figure 16As shown, in the second heating mode, the high-temperature and high-pressure refrigerant gas discharged from the compressor 10 enters the second indoor refrigerant-air heat exchanger 61 through the first switching valve 16 in the first path, and is condensed in the second indoor refrigerant-air heat exchanger 61. The second indoor refrigerant-air heat exchanger 61 condenses the compressed refrigerant into a liquid phase; the refrigerant flowing out of the second indoor refrigerant-air heat exchanger 61 passes through the second indoor throttling element 62 in the throttling working range; the second path passes through the first switching valve 16 and the second switching valve 24 into the first indoor refrigerant-air heat exchanger 422, and is condensed in the first indoor refrigerant-air heat exchanger 422. The first indoor refrigerant-air heat exchanger 422 condenses the compressed refrigerant into a liquid phase; the refrigerant flowing out of the first indoor refrigerant-air heat exchanger 422 passes through the second indoor throttling element 62 in the throttling working range. The refrigerant passes through the first indoor throttling element 43 which is in the throttling working range; the third route enters the refrigerant-water heat exchanger 18 and is condensed in the refrigerant-water heat exchanger 18; the refrigerant-water heat exchanger 18 condenses the compressed refrigerant into a liquid phase; the refrigerant flowing out of the refrigerant-water heat exchanger 18 passes through the second outdoor throttling element 21 which is in the throttling working range, and then passes through the first valve element 25 which is in the conducting state; after the three routes of refrigerant passing through the first indoor throttling element 43, the second indoor throttling element 62 and the second outdoor throttling element 21 are merged, they pass through the first outdoor throttling element 15 which is in the throttling working range, and the outdoor refrigerant-air heat exchanger 14 which works as an evaporator, and after flowing out of the outdoor refrigerant-air heat exchanger 14, they pass through the first switching valve 16 and return to the compressor 10.

[0188] In the first heating mode, waste heat can be used to adjust the fresh air load, thereby significantly improving the performance of the system.

[0189] The processing device 5 is configured to operatively enable the first fan to continuously provide at least a preset minimum amount of fresh air and to select one of the first heating mode and the second heating mode. For example, the configuration can be based on the water source temperature or the indoor ambient temperature.

[0190] The processing device 5 is configured to operably enable the first indoor fan to continuously provide at least a preset minimum amount of fresh air, and collect the real-time supply air temperature of the integrated indoor terminal 4.

[0191] When the real-time supply air temperature meets a preset first real-time indoor ambient temperature determination condition, the first heating mode is executed.

[0192] Exemplarily, when the real-time supply air temperature is not lower than the sum of the real-time ambient temperature and the corrected temperature (real-time supply air temperature ≥ real-time ambient temperature + corrected temperature), it is determined that the real-time supply air temperature meets the first real-time indoor ambient temperature determination condition.

[0193] When the real-time supply air temperature meets the preset second real-time indoor ambient temperature determination condition, the second heating mode is executed.

[0194] Exemplarily, when the real-time supply air temperature is not higher than the real-time ambient temperature (real-time supply air temperature ≤ real-time ambient temperature), it is determined that the real-time supply air temperature meets the second real-time indoor ambient temperature determination condition.

[0195] When the real-time supply air temperature is not lower than the sum of the real-time ambient temperature and the corrected temperature, the judgment condition is used as the upper limit of the hysteresis to ensure that the processing device 5 responds only when the conditions are significant; when the real-time supply air temperature is not higher than the real-time ambient temperature, it is used as the lower limit of the hysteresis to avoid unnecessary adjustments caused by small fluctuations, and a dead zone interval is formed through hysteresis control to optimize stability.

[0196] The fresh air ratio can be adjusted using the fresh air valve 403. Specifically, the fresh air ratio is the percentage of fresh air volume to the total air volume (outdoor air + indoor return air). The static pressure of the fresh air duct 401 and the indoor return air duct directly affects the air volume in the indoor duct and the indoor return air duct. If the static pressure is high, the air volume will decrease; if the static pressure is low, the air volume will increase. In the integrated indoor terminal 4, the total air volume is provided by the first indoor fan 421, but the fresh air volume is distributed through the fresh air valve 403.

[0197] Based on the above principle, in the laboratory, the static pressure of the fresh air duct and the indoor return air duct is preset to be the same, and the fresh air ratio is changed by adjusting the fresh air valve 403. For example, under the condition that the static pressure of the fresh air duct and the indoor return air duct remains the same, the change in the angle of the fresh air valve 403 from the minimum opening to the maximum opening can directly correspond to the linear increase of the fresh air ratio from the preset minimum value. A mapping between the fresh air valve opening and the fresh air ratio under a standard static pressure ratio is established, which covers the fresh air ratio points of common usage scenarios (e.g., 10%, 15%, 20%, 50%, etc.).

[0198] In the actual installation environment, the fresh air valve 403 is driven to work according to the reference fresh air valve opening in the fresh air valve opening-fresh air ratio mapping;

[0199] Measure the actual fresh air volume, actual total air volume, actual fresh air duct static pressure, and actual indoor return air duct static pressure corresponding to the reference fresh air valve opening;

[0200] If there is a deviation between the actual fresh air ratio and the reference fresh air ratio in the fresh air valve opening-fresh air ratio mapping, the opening of the fresh air valve 403 is gradually changed based on the reference fresh air valve opening until the actual fresh air ratio approaches the reference fresh air ratio, thereby obtaining the actual opening of the fresh air valve 403;

[0201] Repeat the test at multiple points in the fresh air valve opening-fresh air ratio mapping;

[0202] Calculate the on-site static pressure ratio based on the actual fresh air duct static pressure and the actual indoor return air duct static pressure;

[0203] Fitting empirical coefficients based on the actual fresh air valve 403 opening and on-site static pressure ratio at multiple points;

[0204] The correction formula for the opening degree of the fresh air valve 403 is derived based on the empirical coefficient. The correction formula for the opening degree of the fresh air valve 403 can be a linear correction formula or a nonlinear correction formula.

[0205] For example, there may be:

[0206] θ site =θ lab ×S site k

[0207] or

[0208] θ site =a×θ lab +b

[0209] Based on the correction formula for the opening of the fresh air valve 403, a correction fresh air valve opening-fresh air ratio mapping suitable for the on-site installation environment can be obtained, and subsequent control can be performed based on this to protect the indoor temperature by adjusting the opening of the fresh air valve 403.

[0210] Based on the dynamic conditions of the real-time indoor ambient temperature and the real-time fresh air temperature, the processing device 5 automatically adjusts the opening of the fresh air valve 403 to optimize indoor environmental control and energy efficiency. The processing device 5 is configured to determine whether the real-time indoor ambient temperature exceeds the real-time indoor ambient temperature control threshold. If so, the processing device 5 further adjusts the gear position and fresh air ratio of the fresh air valve 403 based on the relative position of the real-time fresh air temperature relative to the real-time fresh air temperature lower threshold and the real-time fresh air temperature upper threshold. The real-time fresh air temperature lower threshold and the real-time fresh air temperature upper threshold can be customized based on system configuration, environmental requirements, or user settings to adapt to different scenarios.

[0211] Specifically, the processing device 5 is configured to close the fresh air valve 403 when the real-time indoor ambient temperature meets the forced intervention dynamic ambient temperature condition; and set the fresh air ratio to 0 to prioritize ensuring that the real-time indoor ambient temperature recovers quickly.

[0212] For example, if the real-time indoor ambient temperature is not higher than the preset forced intervention temperature control threshold (real-time indoor ambient temperature ≤ forced intervention temperature control threshold), it is judged that the real-time indoor ambient temperature meets the forced intervention dynamic ambient temperature condition; the forced intervention temperature control threshold is in the range of 10°C to 15°C.

[0213] The processing device 5 is configured to drive the fresh air valve 403 to operate at the first opening position and set the fresh air ratio to be in the first range when the real-time indoor ambient temperature meets the dynamic ambient temperature condition and the real-time fresh air temperature meets the first dynamic real-time fresh air temperature condition, so as to minimize the impact of the introduction of fresh air on the real-time indoor ambient temperature.

[0214] For example, if the real-time indoor ambient temperature is higher than the forced intervention temperature control threshold (real-time indoor ambient temperature> forced intervention temperature control threshold), and the real-time fresh air temperature is not higher than the preset real-time fresh air temperature lower limit threshold (real-time fresh air temperature≤real-time fresh air temperature lower limit threshold), it is determined that the real-time indoor ambient temperature meets the dynamic ambient temperature condition, and the real-time fresh air temperature meets the first dynamic real-time fresh air temperature condition, and the fresh air valve 403 is driven to operate at the first opening gear, and the fresh air ratio is set to the first interval (for example, a low ratio interval defined by the system, such as 2%-10%) to minimize the impact of the introduction of fresh air on the real-time indoor ambient temperature. For example, the first opening gear is the lowest gear.

[0215] The processing device 5 is configured to drive the fresh air valve 403 to operate at the second opening position and set the fresh air ratio to be in the second range when the real-time indoor ambient temperature meets the dynamic ambient temperature condition and the real-time fresh air temperature meets the second dynamic real-time fresh air temperature condition, so as to balance the introduction of fresh air and the stability of the real-time indoor ambient temperature.

[0216] For example, if the real-time indoor ambient temperature is higher than the forced intervention temperature control threshold (real-time indoor ambient temperature>forced intervention temperature control threshold), and the real-time fresh air temperature is between the real-time fresh air temperature lower threshold and the real-time fresh air temperature upper threshold (real-time fresh air temperature lower threshold ≤ real-time fresh air temperature ≤ real-time fresh air temperature upper threshold), then it is determined that the real-time indoor ambient temperature meets the dynamic ambient temperature condition, and the real-time fresh air temperature meets the second dynamic real-time fresh air temperature condition, and the fresh air valve 403 is driven to operate at the second opening gear, and the fresh air proportion is set in the second interval and adjusted to a medium range value (for example, the system-defined medium proportion interval is 8%-12% as an example) to balance the fresh air introduction and the real-time indoor ambient temperature stability. The second opening gear is the middle gear.

[0217] The processing device 5 is configured to drive the fresh air valve 403 to operate at the third opening position and set the fresh air ratio to the third range when the real-time indoor ambient temperature meets the dynamic ambient temperature condition and the real-time fresh air temperature meets the third dynamic real-time fresh air temperature condition, so as to maximize the improvement of air quality.

[0218] For example, if the real-time indoor ambient temperature is higher than the forced intervention temperature control threshold (real-time indoor ambient temperature > forced intervention temperature control threshold), and the real-time fresh air temperature is not higher than the real-time fresh air temperature upper limit threshold (real-time fresh air temperature upper limit threshold ≤ real-time fresh air temperature), then it is determined that the real-time indoor ambient temperature meets the dynamic ambient temperature condition, and the real-time fresh air temperature meets the third dynamic real-time fresh air temperature condition; the fresh air valve 403 is driven to operate at the third opening gear, and the fresh air ratio is set in the third interval and adjusted to a high range value (for example, a high ratio interval defined by the system, taking 12%-20% as an example) to maximize the improvement of air quality. The third opening gear is the highest gear.

[0219] The first interval, the second interval and the third interval increase in sequence.

[0220] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0221] The above are only specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this 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. Multi-connection system, including: an outdoor refrigerant-air heat exchanger connected to the first outdoor throttling element; a refrigerant-water heat exchanger connected to the second outdoor throttling element; a heat radiation indoor terminal, the refrigerant-water heat exchanger supplies water to the heat radiation indoor terminal; It is characterized by further comprising: Integrated indoor terminal, which includes: Fresh air module, which is used to introduce outdoor air, mix the outdoor air with indoor return air, and filter it to form fresh air; A regulation module, comprising: a first indoor refrigerant-air heat exchanger configured to exchange heat between the refrigerant and the fresh air, the first indoor throttling element being connected; and A first fan, which is used to send the fresh air after heat exchange into the indoor space; A processing device, which is configured in a heating mode and is operable to enable the first fan to continuously provide at least a preset minimum amount of fresh air; sample the real-time return air temperature and the real-time supply air temperature of the integrated indoor terminal; call a preset intervention opening when the real-time return air temperature, the real-time supply air temperature, and / or the temperature difference between the real-time return air temperature and the real-time supply air temperature meets a preset intervention condition, and correct the opening of the first indoor throttling element in the throttling working range and / or the second outdoor throttling element in the throttling working range.

2. The multi-connection system according to claim 1, characterized in that: The processing device is configured to execute the following method to correct the opening degree of the first indoor throttling element in the throttling working range: Determining whether the real-time return air temperature meets a first real-time return air temperature intervention condition; determining whether the difference between the real-time return air temperature and the real-time return air temperature satisfies a first supply air temperature difference intervention condition; If the real-time return air temperature satisfies the first real-time return air temperature intervention condition, or the difference between the real-time supply air temperature and the real-time return air temperature satisfies the first supply air temperature difference intervention condition, calling a first intervention opening to increase the opening of the first indoor throttling element in the throttling working range; Otherwise, the opening degree of the first indoor throttling element in the throttling working range is kept unchanged.

3. The multi-connection system according to claim 2, characterized in that: When the real-time return air temperature is not higher than the first preset intervention return air temperature, determining that the real-time return air temperature meets the first real-time return air temperature intervention condition; When the difference between the real-time supply air temperature and the real-time return air temperature is not higher than a first preset intervention temperature difference, it is determined that the difference between the real-time supply air temperature and the real-time return air temperature meets the first supply air temperature difference intervention condition.

4. The multi-connection system according to claim 3, characterized in that: The processing device is configured to execute the following method to correct the opening degree of the first indoor throttling element in the throttling working range: Determining whether the real-time return air temperature meets a second real-time return air temperature intervention condition; determining whether a difference between the real-time supply air temperature and the real-time return air temperature satisfies a second supply air temperature difference intervention condition; If the real-time return air temperature satisfies the second real-time return air temperature intervention condition, and the difference between the real-time supply air temperature and the real-time return air temperature satisfies the second supply air temperature difference intervention condition, the second intervention opening is called to reduce the opening of the first indoor throttling element in the throttling working range; otherwise, the opening of the first indoor throttling element in the throttling working range is kept unchanged.

5. The multi-connection system according to claim 4, characterized in that: When the real-time return air temperature is not lower than the first preset intervention return air temperature, determining that the real-time return air temperature meets the second real-time return air temperature intervention condition; When the difference between the real-time supply air temperature and the real-time return air temperature is not lower than a second preset intervention temperature difference, it is determined that the difference between the real-time supply air temperature and the real-time return air temperature meets the second supply air temperature difference intervention condition.

6. The multi-connection system according to claim 5, characterized in that: The first indoor throttling element and the second outdoor throttling element are electronic expansion valves; The first intervention opening is a first basic value; the first basic value is the product of the upper limit opening of the electronic expansion valve and a predefined percentage; or the product of the opening calculated in the previous cycle and a predefined multiplier; The second intervention opening is a second basic value; the second basic value is the product of the upper limit opening of the electronic expansion valve and a predefined percentage; or the product of the opening calculated in the previous cycle and a predefined multiplier.

7. The multi-connection system according to claim 6, characterized in that: The first intervention opening degree is the sum of the first basic value and the first correction value; wherein the first correction value is the ratio of the first preset intervention temperature difference and the difference between the real-time supply air temperature and the real-time return air temperature; The second intervention opening is the sum of the second basic value and the second correction value; wherein the second correction value is the difference between the real-time supply air temperature and the real-time return air temperature, and the ratio of the second preset intervention temperature difference.

8. The multi-connection system according to claim 1, characterized in that: The processing device is configured to execute the following method to correct the opening degree of the second outdoor throttling element in the throttling working range: Determining whether the real-time return air temperature meets the first real-time return air temperature intervention condition; Determining whether the real-time supply air temperature meets a first real-time supply air temperature intervention condition; If the real-time return air temperature satisfies the first real-time return air temperature intervention condition, and the real-time supply air temperature satisfies the first real-time supply air temperature intervention condition, driving the second outdoor throttling element in the throttling working range to operate at an opening corresponding to the capacity ratio; Otherwise, the opening of the second outdoor throttling element in the throttling working range is kept unchanged; The capacity ratio corresponding opening is generated based on the ratio of the total capacity of the integrated indoor terminals currently in operation to the capacity of the outdoor units; The larger the ratio of the total capacity of the integrated indoor terminals currently in operation to the capacity of the outdoor units, the smaller the opening corresponding to the capacity ratio.

9. The multi-connection system according to claim 8, characterized in that: The processing device is configured to execute the following method to correct the opening degree of the second outdoor throttling element in the throttling working range: determining whether the real-time return air temperature satisfies a second real-time return air temperature intervention condition and exceeds a preset duration, wherein the real-time return air temperature that satisfies the second real-time return air temperature intervention condition is higher than the real-time return air temperature that satisfies the first real-time return air temperature intervention condition; If the real-time return air temperature meets the second real-time return air temperature intervention condition and exceeds the preset duration, the second outdoor throttling element in the throttling working range is driven to work in the fully open working range.

10. The multi-connection system according to any one of claims 1 to 9, characterized in that: The fresh air module includes a fresh air valve, and the processing device is configured to execute the following method to control the fresh air valve: Sampling real-time fresh air temperature; Determining whether the real-time return air temperature meets the preset return air temperature working condition; Determine whether the temperature difference between the real-time return air temperature and the real-time fresh air temperature satisfies a preset first fresh air temperature influencing condition; or determine whether the real-time fresh air temperature satisfies a preset second fresh air temperature influencing condition; If the real-time return air temperature satisfies the preset return air temperature working condition and the temperature difference between the real-time return air temperature and the real-time fresh air temperature satisfies the preset first fresh air temperature influencing condition; Or if the real-time return air temperature meets the preset return air temperature working condition and the real-time fresh air temperature meets the preset second fresh air temperature influencing condition, the fresh air valve is kept at the working opening; otherwise, the fresh air valve is driven to close.

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