Air conditioning system

Abstract

The invention provides an air conditioning system. The air conditioning system comprises an outdoor module and a processing device. The outdoor module is provided with a compressor, a switching valve, an oil separator and a gas-liquid separator; the processing device comprises an acquisition part, a calculation part and a presumption part; the acquisition part is configured to correspondingly acquire operation parameters of the suction end and the discharge end of the compressor; a calculation section configured to calculate a difference between the suction end operation parameter and the discharge end operation parameter; the presumption part is configured to presume corresponding adjustment operation parameters according to normal operation parameters of a plurality of execution components driven by electric power in the outdoor module on the basis of the difference between the operation parameters of the suction end and the discharge end and a reference balance pressure presumption condition; wherein the reference equilibrium pressure presumption condition is used for judging whether the pressure difference among the plurality of gas-liquid separators is in an unbalanced state or not; in addition, when an execution component in the outdoor module operates according to the adjusting operation parameters, the pressure difference between the multiple gas-liquid separators is reduced. The stability of the air conditioning system can be improved.

Description

Technical Field

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

[0002] Increasingly, multi-split air conditioning systems are adopting a dual-compressor configuration. Each compressor is equipped with a corresponding gas-liquid separator. The entire system can be viewed as two parallel circulation systems. Because the operating parameters of the two systems are not entirely identical, especially due to the inherent pressure difference within the two gas-liquid separators, the oil-liquid mixture levels inside them will differ. The oil concentration in one separator will increase while the concentration in the other decreases, leading to compressor oil shortage and damage.

[0003] Existing technologies provide solutions to this problem, such as the technical solution disclosed in Chinese patent application (CN116067044A): "A compressor assembly includes a first compressor and a second compressor, the first compressor having a first exhaust port and a first return port, and the second compressor having a second exhaust port and a second return port; a first oil separator and a second oil separator, the first oil separator having a first oil outlet and a first oil separation inlet communicating with the first exhaust port, and the second oil separator having a second oil outlet and a second oil separation inlet communicating with the second exhaust port; a first gas-liquid separator and a second gas-liquid separator, the first gas-liquid separator having a first separation chamber and a first gas separation inlet communicating with the first separation chamber." The second gas-liquid separator comprises a first oil return port, a first oil return port, and a first gas separation outlet; a second gas separation chamber and a second gas separation inlet, a second oil return port, and a second gas separation outlet communicating with the second separation chamber; a first oil outlet communicating with the first gas separation inlet; a second oil outlet communicating with the second gas separation inlet; each of the first gas separation outlet and the first oil return port communicating with a first gas return port; and each of the second gas separation outlet and the second oil return port communicating with a second gas return port; and a liquid balance pipe and a gas balance pipe, the gas balance pipe being located above the liquid balance pipe; one end of each of the liquid balance pipe and one end of the gas balance pipe communicating with the first separation chamber; and the other end of each of the liquid balance pipe and the other end of the gas balance pipe communicating with the second separation chamber.

[0004] In existing technology, the liquid levels in the two gas-liquid separators are balanced by liquid balance pipes and gas balance pipes. However, the liquid refrigerant distributed into the two gas-liquid separators cannot be completely uniform, and the system piping layout, direction, and length are not completely consistent. In addition, the suction volume of the two compressors is not completely consistent. This will cause a pressure difference between the two gas-liquid separators. The pressure difference will cause the liquid level height of the two gas-liquid separators to differ when the liquid balance pipe reaches a balanced state. Summary of the Invention

[0005] This invention addresses the problem that pressure differences cause a difference in the liquid level height between the two gas-liquid separators when the liquid balance tube reaches equilibrium, and designs and discloses an air conditioning system.

[0006] The air conditioning system includes an outdoor module, an indoor module, and a processing unit; wherein, the outdoor module has: multiple compressors, switching valves, multiple oil separators, multiple gas-liquid separators, and distribution pipelines; the multiple oil separators are respectively installed at the discharge end of the compressors, the multiple gas-liquid separators are respectively installed at the suction end of the compressors, and a liquid equalization pipe is installed between the gas-liquid separators; the distribution pipelines are fluidly connected to the multiple gas-liquid separators.

[0007] In one or more embodiments of this application, the processing device includes a data acquisition unit, a calculation unit, and an estimation unit; the data acquisition unit is configured to acquire operating parameters of the suction end and discharge end of a plurality of compressors respectively; the calculation unit is configured to calculate the differences between the operating parameters of the suction end of the plurality of compressors and the differences between the operating parameters of the discharge end of the plurality of compressors; the estimation unit is configured to, in cooling mode, estimate corresponding adjustment operating parameters based on the differences between the operating parameters of the suction end, the differences between the operating parameters of the discharge end, and the reference balance pressure estimation condition, according to the conventional operating parameters of the electrically driven actuator in the indoor module.

[0008] In one or more embodiments of this application, the reference equilibrium pressure estimation condition is used to determine whether the pressure difference between the plurality of gas-liquid separators is in an unbalanced state; and when the actuator in the indoor module is running according to the adjusted operating parameters, the refrigerant flow rate in the distribution pipeline decreases, and the pressure difference between the plurality of gas-liquid separators decreases.

[0009] In one or more embodiments of this application, the actuating component is an indoor throttling element; the estimation unit, based on the current opening degree of the indoor throttling element, reduces the refrigerant flow rate in the distribution pipeline and reduces the pressure difference between the plurality of gas-liquid separators by changing the current opening degree of the indoor throttling element.

[0010] In one or more embodiments of this application, the estimation unit, based on the current opening degree of the indoor throttling element, reduces the refrigerant flow rate in the distribution pipeline and reduces the pressure difference between the plurality of gas-liquid separators by changing the current opening degree of the indoor throttling element. This includes: obtaining the current proportional relationship between the differences between the operating parameters at the suction end and the differences between the operating parameters at the discharge end; determining the fitting adjustment range corresponding to the current proportional relationship based on a functional relationship established based on the proportional relationship and the opening adjustment range; and gradually reducing the opening degree of the indoor throttling element by repeatedly using the product of the previous indoor throttling element opening degree and the fitting adjustment range as the actual opening degree until the opening degree of the indoor throttling element reaches the minimum opening degree, or the pressure difference between the plurality of gas-liquid separators is no longer in a non-equilibrium state.

[0011] In one or more embodiments of this application, the functional relationship established based on the proportional relationship and the opening adjustment range is obtained in the following way: Under simulation conditions, the differences between the operating parameters at the inhalation end and the operating parameters at the discharge end are collected; the proportional relationship between the corresponding differences between the operating parameters at the inhalation end and the operating parameters at the discharge end is calculated; a set of adjustment ranges and adjustment frequencies are randomly generated in a preset data pool; the set duration is divided into multiple continuous cycles based on the adjustment frequency, and the opening of the indoor throttling element is gradually reduced by using the product of the opening of the indoor throttling element in the previous cycle and the random adjustment range as the actual opening; it is estimated that at the end of the set duration, the pressure difference between the multiple gas-liquid separators is no longer in a non-equilibrium state; if it is no longer in a non-equilibrium state, the corresponding ratio and random adjustment range are recorded as valid data points; multiple valid data points are obtained, and the functional relationship between the proportional relationship and the opening adjustment range is fitted.

[0012] In one or more embodiments of this application, the estimation unit is further configured to adjust the operating parameters by changing the current operating frequency of the compressors based on the current operating frequency of the plurality of compressors, thereby reducing the refrigerant flow rate in the distribution pipeline and reducing the pressure difference between the plurality of gas-liquid separators.

[0013] In one or more embodiments of this application, an estimation unit is configured to, in heating mode, estimate corresponding regulating operating parameters based on the differences between operating parameters at the suction end, the differences between operating parameters at the discharge end, and a reference balance pressure estimation condition, according to the normal operating parameters of the electrically driven actuator in the outdoor module; wherein, the reference balance pressure estimation condition is used to determine whether the pressure difference between the plurality of gas-liquid separators is in an unbalanced state; and, when the actuator in the outdoor module operates according to the regulating operating parameters, the refrigerant flow rate in the distribution pipeline decreases, and the pressure difference between the plurality of gas-liquid separators decreases.

[0014] In one or more embodiments of this application, the execution component includes an outdoor fan; the estimation unit adjusts the operating parameters by changing the current speed of the outdoor fan based on the current speed of the outdoor fan, thereby reducing the refrigerant flow in the distribution pipeline and reducing the pressure difference between the plurality of gas-liquid separators.

[0015] In one or more embodiments of this application, the execution component further includes an outdoor throttling element; the estimation unit, based on the current opening degree of the outdoor throttling element, estimates and adjusts the operating parameters by changing the current opening degree of the outdoor throttling element, thereby reducing the refrigerant flow rate in the distribution pipeline and reducing the pressure difference between the plurality of gas-liquid separators.

[0016] In one or more embodiments of this application, the estimation unit, based on the current opening degree of the outdoor throttling element, reduces the refrigerant flow rate in the distribution pipeline and reduces the pressure difference between the plurality of gas-liquid separators by changing the current opening degree of the outdoor throttling element. This includes: obtaining the current proportional relationship between the differences between the operating parameters at the suction end and the differences between the operating parameters at the discharge end; determining the fitting adjustment range corresponding to the current proportional relationship based on the functional relationship established based on the proportional relationship and the opening adjustment range; and gradually reducing the opening degree of the outdoor throttling element by repeatedly using the product of the previous outdoor throttling element opening degree and the fitting adjustment range as the actual opening degree until the opening degree of the outdoor throttling element reaches the minimum opening degree, or the pressure difference between the plurality of gas-liquid separators is no longer in a non-equilibrium state.

[0017] In one or more embodiments of this application, the execution component further includes a plurality of compressors; the estimation unit, based on the current operating frequency of the plurality of compressors, estimates and adjusts the operating parameters by changing the current operating frequency of the compressors, thereby reducing the refrigerant flow rate in the distribution pipeline and reducing the pressure difference between the plurality of gas-liquid separators.

[0018] This application achieves accurate data acquisition and calculation through the collaborative work of the data acquisition unit, the calculation unit, and the estimation unit, and estimates the optimal adjustment and operation parameters. It then adjusts the actuators in real time to automatically reduce the pressure difference between the gas and liquid separators, thereby improving the stability and operating efficiency of the air conditioning system and reducing mechanical wear and energy loss.

[0019] Other features and advantages of the present invention will become clearer after reading the detailed embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of an air conditioning system provided in one or more embodiments of this application;

[0022] Figure 2 This is a schematic diagram of the structure of an air conditioning system in cooling mode provided in one or more embodiments of this application;

[0023] Figure 3 This is a schematic diagram of the structure of an air conditioning system in heating mode provided in one or more embodiments of this application;

[0024] Figure 4This is a schematic diagram of the structure of an air conditioning system provided in one or more embodiments of this application;

[0025] Figure 5 This is a schematic diagram of the structure of the processing device in an air conditioning system provided by one or more embodiments of this application;

[0026] Figure 6 This is a flowchart of a processing device in an air conditioning system provided in one or more embodiments of this application;

[0027] Figure 7 This is a flowchart of a processing device in an air conditioning system provided in one or more embodiments of this application;

[0028] Figure 8 This is an example of a polynomial fitting function;

[0029] Figure 9 This is a schematic diagram of the structure of an air conditioning system provided in one or more embodiments of this application;

[0030] Figure 10 This is a flowchart of a processing device in an air conditioning system provided in one or more embodiments of this application;

[0031] Figure 11 This is a flowchart of a processing device in an air conditioning system provided in one or more embodiments of this application;

[0032] Figure 12 This is a schematic diagram of the structure of an air conditioning system provided in one or more embodiments of this application;

[0033] Figure 13 This is a flowchart of a processing device in an air conditioning system provided in one or more embodiments of this application;

[0034] Figure 14 This is a flowchart of a processing device in an air conditioning system provided in one or more embodiments of this application;

[0035] Figure 15 This is a schematic diagram of the structure of an air conditioning system provided in one or more embodiments of this application;

[0036] Figure 16 This is an example of a polynomial fitting function;

[0037] Figure 17 This is a flowchart of a processing device in an air conditioning system provided in one or more embodiments of this application;

[0038] Figure 18 This is a schematic diagram of the structure of an air conditioning system provided in one or more embodiments of this application;

[0039] Figure 19This is a flowchart of a processing device in an air conditioning system provided in one or more embodiments of this application;

[0040] In the diagram: 10. Outdoor module; 20. Indoor module; 30. Processing unit; 101. First compressor; 102. Second compressor; 103. First high-pressure switch; 104. Second high-pressure switch; 105. First oil separator; 106. Second oil separator; 107. First oil return branch; 108. Second oil return branch; 109. Filter; 110. Filter; 111. First oil return capillary tube; 112. Second oil return capillary tube; 113. Exhaust pressure sensor; 114. 115. Switching valve; 116. Outdoor heat exchanger; 117. Outdoor throttling element; 118. Liquid pipe shut-off valve; 119. Liquid pipe; 120. Indoor throttling element; 121. Indoor heat exchanger; 122. Indoor heat exchanger; 123. Indoor throttling element; 124. Indoor heat exchanger; 125. Gas pipe; 126. Gas pipe shut-off valve; 127. Distribution pipeline; 128. Low-pressure side pressure sensor; 129. First drain pipe; 130. Second drain pipe; 131. Distribution... 132. First gas-liquid separator; 133. Second gas-liquid separator; 134. First U-tube; 135. Second U-tube; 136. Gas equalization pipe; 137. Liquid equalization pipe; 138. First exhaust temperature sensor; 139. Second exhaust temperature sensor; 140. First intake temperature sensor; 141. Second intake temperature sensor; 142. Manifold; 143. First regulating branch; 144. First electronic expansion valve; 145. Filter; 146. Second regulating branch ; 147. Second electronic expansion valve; 148. Filter; 149. First outlet pipe; 150. Second outlet pipe; 151. Regulating branch; 152. Filter; 153. Solenoid valve; 154. Regulating capillary tube; 155. First regulating branch; 156. Filter; 157. First solenoid valve; 158. First regulating capillary tube; 159. Second regulating branch; 160. Filter; 161. Second solenoid valve; 162. Second regulating capillary tube; 163. Outdoor fan;

[0041] 301. Processor; 302. Non-volatile memory; 303. Volatile memory; 304. Display device; 305. Operating device; 306. Communication interface; 307. Drive device; 308. Bus; 309. Storage medium; 310. Storage medium. Detailed Implementation

[0042] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0043] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0044] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "multiple" means two or more.

[0045] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0046] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0047] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and letters may be repeated in different examples; this repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and the use of other materials.

[0048] Hereinafter, one or more embodiments of this application will be described in detail with reference to the accompanying drawings.

[0049] This application relates to an air conditioning system, and more particularly to a multi-split air conditioning system. A multi-split air conditioning system is an air conditioning system capable of independently cooling or heating multiple rooms or zones, with the temperature of each room or zone controllable independently or in combination. Multi-split air conditioning systems are particularly suitable for buildings containing multiple rooms or zones that require independent temperature control, such as office buildings, schools, hotels, and large residences.

[0050] Figure 1 This document shows a schematic diagram of the structure of an air conditioning system provided by one or more specific embodiments of this application.

[0051] Multi-split air conditioning systems integrate a refrigeration cycle. This cycle uses a compressor, condenser, expansion valve, and evaporator. The refrigeration cycle involves a series of processes—compression, condensation, expansion, and evaporation—to cool or heat an indoor space.

[0052] From a principle perspective, low-temperature, low-pressure refrigerant enters the compressor, which compresses it into a high-temperature, high-pressure refrigerant gas and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser, where the condenser condenses the compressed refrigerant into a liquid phase, and the heat is released to the surrounding environment through the condensation process.

[0053] The throttling device expands the high-temperature, high-pressure liquid refrigerant that condenses in the condenser into a low-pressure liquid refrigerant. The evaporator evaporates the expanded refrigerant in the throttling device, returning the low-temperature, low-pressure refrigerant to the compressor. The evaporator achieves its cooling effect by utilizing the latent heat of refrigerant evaporation to exchange heat with the material being cooled. Throughout the cycle, the air conditioning system regulates the temperature of the indoor space.

[0054] like Figure 1 As shown, in one or more embodiments of this application, the air conditioning system includes an outdoor module 10 and an indoor module 20 connected to each other.

[0055] The outdoor module 10 and the indoor module 20 are connected by a liquid pipe 118 and a gas pipe 125. The liquid pipe 118 and the gas pipe 125 are used to supply refrigerant flow, so that the refrigerant can form a refrigerant loop and circulate in it.

[0056] In one or more embodiments of this application, a liquid pipe shut-off valve 117 is provided on the liquid pipe 118.

[0057] In one or more embodiments of this application, an airway shut-off valve 126 is provided on the airway 125.

[0058] The following section introduces the outdoor module 10, such as... Figures 1 to 3 As shown

[0059] In one or more embodiments of this application, the outdoor module 10 is a portion of the refrigeration cycle that includes a compressor and an outdoor heat exchanger 115. The outdoor module 10 can perform heating or cooling operation on the outdoor side to provide energy to the indoor module 20 for raising or lowering the indoor temperature. The outdoor heat exchanger 115 is correspondingly provided with an outdoor throttling element 116.

[0060] In one or more embodiments of this application, the outdoor module 10 includes a plurality of compressors, such as... Figure 1 The first compressor 101 and the second compressor 102 are shown. The first compressor 101 and the second compressor 102 are the same compressor.

[0061] A first high-pressure switch 103 is installed at the discharge end of the first compressor 101, and a second high-pressure switch 104 is installed at the discharge end of the second compressor 102. The first high-pressure switch 103 and the second high-pressure switch 104 are used to monitor the pressure in the system. When the pressure in the air conditioning system exceeds a set safety threshold, the first high-pressure switch 103 and / or the second high-pressure switch 104 will automatically cut off the power supply, stopping the operation of the first compressor 101 and / or the second compressor 102, to protect the equipment and devices in the air conditioning system from damage caused by high pressure. The safety threshold of the first high-pressure switch 103 and / or the second high-pressure switch 104 can be set according to the design parameters and operating conditions of the air conditioning system. Once the pressure in the system drops to a safe level, the first high-pressure switch 103 and / or the second high-pressure switch 104 will restore power, restarting the first compressor 101 and / or the second compressor 102.

[0062] In one or more embodiments of this application, a first exhaust temperature sensor 138 is provided at the discharge end of the first compressor 101, and a second exhaust temperature sensor 139 is provided at the discharge end of the second compressor 102.

[0063] In one or more embodiments of this application, a first intake temperature sensor 140 is provided at the intake end of the first compressor 101, and a second intake temperature sensor 141 is provided at the intake end of the second compressor 102.

[0064] In one or more embodiments of this application, the outdoor module 10 is further provided with an oil separator. The oil separator is configured in a one-to-one correspondence with the compressor, and is located at the discharge end of the compressor. For example, as shown... Figure 1 As shown, the outdoor module 10 is equipped with a first oil separator 105 and a second oil separator 106. The first oil separator 105 is located at the discharge end of the first compressor 101, and the second oil separator 106 is located at the discharge end of the second compressor 102. The function of the first oil separator 105 and the second oil separator 106 in the air conditioning system is to separate the lubricating oil and the refrigerant. Since the first compressor 101 and the second compressor 102 require lubricating oil to reduce friction and wear and ensure normal operation, the lubricating oil mixes with the refrigerant during operation. The first oil separator 105 and the second oil separator 106 separate the lubricating oil from the refrigerant through the principle of physical separation (such as centrifugal force or gravity). The separated lubricating oil is recovered and recycled, while the refrigerant continues to flow. The first oil separator 105 and the second oil separator 106 are equipped with a one-way valve (not shown). In one or more embodiments of this application, the first outlet pipe 149 of the first oil separator 105 and the second outlet pipe 150 of the second oil separator 106 are connected to the switching valve 114 after they merge.

[0065] In one or more embodiments of this application, the outdoor module 10 is further provided with a gas-liquid separator. Each gas-liquid separator is configured in a one-to-one correspondence with a compressor. For example... Figure 1 As shown, the outdoor module 10 is equipped with a first gas-liquid separator 132 and a second gas-liquid separator 133, which are identical. The first gas-liquid separator 132 and the second gas-liquid separator 133 achieve separation based on the density difference between gas and liquid. When a refrigerant mixture containing both gas and liquid enters the first gas-liquid separator 132 and the second gas-liquid separator 133, due to gravity, the denser liquid refrigerant sinks, while the less dense gas rises. In this way, the first gas-liquid separator 132 and the second gas-liquid separator 133 can effectively separate liquid and gaseous refrigerant. The first gas-liquid separator 132 and the second gas-liquid separator 133 can also store excess refrigerant. The first gas-liquid separator 132 and the second gas-liquid separator 133 are connected to each other via an upper gas equalization pipe 136 and a lower liquid equalization pipe 137.

[0066] The first gas-liquid separator 132 is provided with a first U-shaped tube 134, which is connected to the first compressor 101. The second gas-liquid separator 133 is provided with a second U-shaped tube 135, which is connected to the second compressor 102.

[0067] In one or more embodiments of this application, the outdoor module 10 is further provided with a switching valve 114, which is typically a four-way valve, allowing the air conditioning system to switch between cooling and heating modes. When the air conditioning system operates in cooling mode, the outdoor heat exchanger 115 functions as a condenser; when the air conditioning system operates in heating mode, the outdoor heat exchanger 115 functions as an evaporator.

[0068] In one or more embodiments of this application, the outdoor module 10 is further provided with an outdoor fan 163 (e.g., Figure 18 As shown, the speed of the outdoor fan can be controlled to change the airflow that exchanges heat with the outdoor heat exchanger 115. The outdoor fan can be an axial fan, a cross-flow fan, or other optional fan type. The outdoor fan is located near the outdoor heat exchanger 115.

[0069] In one or more embodiments of this application, an exhaust pressure sensor 113 is provided downstream of the first oil separator 105 and the second oil separator 106.

[0070] In cooling operation, the outdoor module 10 can form a refrigerant circuit for cooling operation, which is sequentially connected from the gas pipe 125 to the liquid pipe 118 to a switching valve 114 (e.g., the passage between port C and port S of a four-way valve), a first gas-liquid separator 132 and a second gas-liquid separator 133 connected in parallel, a first compressor 101 and a second compressor 102 connected in parallel, the switching valve 114 (e.g., the passage between port D and port E of a four-way valve), an outdoor heat exchanger 115, and an outdoor throttling element 116, such as... Figure 2 As shown.

[0071] In heating operation, the outdoor unit can form a refrigerant circuit for heating operation, which is sequentially connected from the liquid side piping to the gas side piping to the outdoor electronic expansion valve, outdoor heat exchanger 115, switching valve 114 (e.g., the passage between the E port and the S port of a four-way valve), a first gas-liquid separator 132 and a second gas-liquid separator 133 connected in parallel, a first compressor 101 and a second compressor 102 connected in parallel, and switching valve 114 (e.g., the passage between the D port and the C port of a four-way valve).

[0072] The structure and function of the indoor module 20 are described below.

[0073] The indoor module 20 uses the energy generated by the outdoor unit to increase or decrease the indoor temperature to perform cooling or heating operation.

[0074] In one or more embodiments of this application, the indoor module 20 includes multiple indoor heat exchangers connected in parallel (as shown in Figures 120, 122, and 124). Each indoor heat exchanger 120 is matched with an indoor throttling element (as shown in Figures 119, 121, and 123), which is configured to reduce the pressure of the refrigerant and cause it to expand. A group of indoor heat exchangers and indoor throttling elements can be installed in an air-conditioned room and matched with an indoor fan, which can be an axial fan, a cross-flow fan, or other type of fan. The indoor fan is positioned close to the indoor heat exchangers.

[0075] In one or more embodiments of this application, the refrigerant flow is guided between the switching valve 114 and the parallel first gas-liquid separator 132 and second gas-liquid separator 133 via a distribution line 127. The distribution line 127 is connected to the inlet end of the distributor 131. The distributor 131 has multiple outlet ends; exemplaryly, the distributor 131 may have two outlet ends, one of which is connected to a first drain pipe 129, and the other outlet end is connected to a second drain pipe 130. The first drain pipe 129 extends into the first gas-liquid separator 132, and the second drain pipe 130 extends into the second gas-liquid separator 133. A low-pressure side pressure sensor 128 is provided on the distribution line 127.

[0076] The first oil separator 105 is connected to the first inlet pipe 129 via the first return oil branch 107. The first return oil branch 107 is equipped with a filter 109 and a first return oil capillary 111. The second oil separator 106 is connected to the second inlet pipe 130 via the second return oil branch 108. The second return oil branch 108 is equipped with a filter 110 and a second return oil capillary 112.

[0077] During operation, a pressure difference exists between the first gas-liquid separator 132 and the second gas-liquid separator 133. This pressure difference can be very significant; even a 1 kPa pressure difference can result in a 10 cm liquid level difference. Even with a Φ25.4 mm diameter equalization pipe 125, the pressure difference between the first gas-liquid separator 132 and the second gas-liquid separator 133 is often above 1 kPa. This results in a lower liquid level in the gas-liquid separator with higher pressure and a higher liquid level in the gas-liquid separator with lower pressure.

[0078] Further analysis of the oil-liquid mixture in the gas-liquid separator reveals that, under static conditions, the lubricating oil and liquid refrigerant are completely miscible. However, under dynamic conditions, the liquid mixture flowing into the gas-liquid separator through the first inlet pipe 129 and the second inlet pipe 130 has a high liquid refrigerant content, accumulating at the top of the oil-liquid mixture and seeping downwards over time. Therefore, the upper part has more liquid refrigerant and a lower lubricating oil concentration, while the bottom has less liquid refrigerant and a higher lubricating oil concentration. As mentioned above, a pressure difference exists between the first gas-liquid separator 132 and the second gas-liquid separator 133, causing the liquid level in the first gas-liquid separator 132 to be 10 cm lower than that in the second gas-liquid separator 133. This results in the oil-liquid mixture with the highest lubricating oil concentration at the bottom of the first gas-liquid separator 132 being continuously forced into the second gas-liquid separator 133, ultimately leading to the inflow of liquid refrigerant from the top, continuous dilution, and a decreasing concentration of the oil-liquid mixture at the bottom of the first gas-liquid separator 132, while the concentration in the second gas-liquid separator 133 increases. Because the first gas-liquid separator 132 and the second gas-liquid separator 133 are respectively equipped with a first U-shaped tube 134 and a second U-shaped tube 135 for oil return, and oil return holes are opened at the bottom of the first U-shaped tube 134 and the second U-shaped tube 135, the amount of lubricating oil returning to the first compressor 101 through the first U-shaped tube 134 will gradually decrease, leading to oil shortage in the compressor.

[0079] To address this problem, one or more embodiments of this application also provide a processing device 30, such as... Figure 4 As shown.

[0080] like Figure 5 As shown in the figure, the hardware configuration of the processing device 30 is as follows. The processing device 30 includes components such as a processor 301, volatile memory 303, non-volatile memory 302, display device 304, operation device 305, communication interface 306, and drive device 307, which are interconnected via a bus 308. The processor 301 may be a dedicated processor 301, a central processing unit, etc. The processor 301 can access the storage unit to execute instructions or application programs stored in the storage unit to achieve related functions. The display device 304 is a display device 304 for displaying various information, the operation device 305 is an operation device for receiving various operations, and the drive device 307 is a hardware terminal that interacts with the storage medium. In one or more embodiments of this application, the storage medium 309 includes media such as CD-ROM, floppy disk, and optical-magnetic-optical disk that record information in an optical, electrical, or magnetic manner. The storage medium 310 may also be a semiconductor memory such as ROM or flash memory that records information in an electrical manner.

[0081] In one or more embodiments of this application, the processing device 30 may be a controller in the outdoor module 10.

[0082] In one or more embodiments of this application, the processing device 30 may be implemented by a terminal device and / or a cloud server.

[0083] In one or more embodiments of this application, some functions of the processing device 30 may be implemented by the controller in the outdoor module 10, and some functions may be implemented by the terminal device and / or cloud server.

[0084] The network between the controller, terminal equipment and / or cloud server in the outdoor module 10 can be the Internet, cellular network, Wi-Fi network, low power wide area network based on standards and protocols such as LoRa, Sigfox, NB-IoT, wide area network and local area network, etc.

[0085] In one or more embodiments of this application, the processing device 30 includes an acquisition unit, a calculation unit, and an estimation unit. Each of these components can be implemented by a processor running a program.

[0086] The data acquisition unit is configured to collect operating parameters from the inlet and outlet ends of multiple compressors.

[0087] The computing unit is configured to calculate the differences between the operating parameters at the suction end of multiple compressors and the differences between the operating parameters at the discharge end of multiple compressors.

[0088] The estimation unit is configured to estimate the corresponding adjustment operating parameters based on the differences between the operating parameters at the inhalation end, the differences between the operating parameters at the discharge end, and the baseline balance pressure estimation conditions, according to the conventional operating parameters of the multiple electrically driven actuators of the outdoor module 10.

[0089] The baseline equilibrium pressure estimation condition is used to determine whether the pressure difference between the multiple gas-liquid separators is in an unbalanced state. Furthermore, when the actuator in the outdoor module 10 operates according to the adjusted operating parameters, the pressure difference between the multiple gas-liquid separators decreases.

[0090] In one or more embodiments of this application, estimating the corresponding adjustment operating parameters based on the conventional operating parameters of a plurality of electrically driven actuators of the outdoor module 10 means estimating the corresponding adjustment operating parameters by changing the conventional operating parameters based on the conventional operating parameters of the plurality of electrically driven actuators of the outdoor module 10.

[0091] Changes can be made by increasing, decreasing, adjusting, or using empirical formulas or models to calculate and estimate the corresponding operating parameters.

[0092] Continuing the example above, if the oil content at the bottom of the first gas-liquid separator 132 decreases, the first compressor 101 connected to it will not receive effective lubrication and will experience wear due to lack of oil, resulting in higher operating parameters at the discharge end. Simultaneously, with less oil return, the refrigerant charge will be higher, and the refrigerant state at the compressor suction end will be in a non-superheated state, leading to lower operating parameters at the suction end. Therefore, based on the differences between the suction end operating parameters, the differences between the discharge end operating parameters, and the baseline equilibrium pressure estimation condition, it is possible to determine whether the pressure difference between the multiple gas-liquid separators is in an unbalanced state. The estimation unit further estimates the corresponding adjustment operating parameters based on the conventional operating parameters of the multiple electrically driven actuators of the outdoor module 10, so as to reduce the pressure difference between the multiple gas-liquid separators.

[0093] This application achieves accurate data acquisition and calculation through the collaborative work of the data acquisition unit, the calculation unit, and the estimation unit, and estimates the optimal adjustment and operation parameters. It then adjusts the actuators in real time to automatically reduce the pressure difference between the gas and liquid separators, thereby improving the stability and operating efficiency of the air conditioning system and reducing mechanical wear and energy loss.

[0094] In one or more embodiments of this application, the operating parameters of the suction end of the plurality of compressors are the suction temperatures of the suction end of the plurality of compressors; the operating parameters of the discharge end of the plurality of compressors are the discharge temperatures of the discharge end of the plurality of compressors.

[0095] In one or more embodiments of this application, the operating parameters may also be selected as pressure, or other parameters that can be converted based on a pressure-enthalpy diagram.

[0096] In one or more embodiments of this application, the baseline equilibrium pressure is estimated to be: the difference in compressor intake temperature is higher than a set temperature threshold, and the difference in compressor discharge temperature is higher than a set temperature threshold.

[0097] In one or more embodiments of this application, the outdoor module 10 includes a plurality of regulating branches. The regulating branches are disposed between corresponding oil separators and gas-liquid separators. Each regulating branch is provided with an actuator. When the actuator operates according to the regulating operating parameters, it reduces the pressure difference between the plurality of gas-liquid separators by changing the refrigerant flow rate in at least one regulating branch.

[0098] In one or more embodiments of this application, the actuating component is an electronic expansion valve. The operating parameter is adjusted by the opening degree of the electronic expansion valve.

[0099] When the estimation department estimates and adjusts the operating parameters, it includes the following steps:

[0100] Acquire the differences between the operating parameters at the inhalation end and the operating parameters at the exhaust end.

[0101] Based on the differences between the operating parameters at the inhalation end and the operating parameters at the discharge end, the opening of the electronic expansion valve corresponding to the one with the higher pressure among the multiple gas-liquid separators is reduced, and the opening of the electronic expansion valve corresponding to the one with the lower pressure among the multiple gas-liquid separators is increased.

[0102] like Figure 4 As shown, the outdoor module 10 includes a first regulating branch 143 and a second regulating branch 146. The first regulating branch 143 is located between the first outlet pipe 149 and the first drain pipe 129, and the second regulating branch 146 is located between the second outlet pipe 150 and the second drain pipe 130. A first electronic expansion valve 144 is installed on the first regulating branch 143, and a second electronic expansion valve 147 is installed on the second regulating branch 146. The first electronic expansion valve 144 is connected in series with the filter 145, and the second electronic expansion valve 147 is connected in series with the filter 148.

[0103] When the estimation unit estimates the adjustment operating parameters, it obtains the differences between the operating parameters at the inhalation end and the operating parameters at the discharge end. Based on the differences between the operating parameters at the inhalation end and the operating parameters at the discharge end, it decreases the opening of the electronic expansion valve (one of the first electronic expansion valve 144 and the second electronic expansion valve 147) corresponding to the one with higher pressure among the plurality of gas-liquid separators, and increases the opening of the electronic expansion valve (the other of the first electronic expansion valve 144 and the second electronic expansion valve 147) corresponding to the one with lower pressure among the plurality of gas-liquid separators.

[0104] In one or more embodiments of this application, based on the differences between the operating parameters at the inhalation end and the differences between the operating parameters at the discharge end, the opening of the electronic expansion valve corresponding to the one with the higher pressure among a plurality of gas-liquid separators is reduced, and the opening of the electronic expansion valve corresponding to the one with the lower pressure among a plurality of gas-liquid separators is increased, specifically including the following steps:

[0105] The opening of the electronic expansion valve corresponding to the one with the higher pressure among a plurality of gas-liquid separators can be reduced to a lower opening limit threshold; for example, it can be completely closed.

[0106] Obtain the current proportional relationship between the differences between the operating parameters at the inhalation end and the differences between the operating parameters at the exhaust end.

[0107] Based on the functional relationship established by the proportional relationship and the opening adjustment range, the fitted adjustment range corresponding to the current proportional relationship is determined. By repeatedly using the product of the previous electronic expansion valve opening and the fitted adjustment range as the actual opening, the opening of the electronic expansion valve corresponding to the one with the lower pressure among the multiple gas-liquid separators is gradually increased until the opening of the electronic expansion valve corresponding to the one with the lower pressure among the multiple gas-liquid separators reaches the maximum opening, or the pressure difference between the multiple gas-liquid separators is no longer in a non-equilibrium state. The initial opening of the electronic expansion valve is the minimum flow opening.

[0108] In large multi-split air conditioning systems, highly accurate sensors are typically not selected. On one hand, high-precision sensors have stringent environmental requirements and are easily affected by factors such as temperature, humidity, and electromagnetic interference, impacting their lifespan. On the other hand, high-precision sensors require frequent calibration, which does not meet the needs of users requiring long-term continuous use. However, as mentioned above, even a 1 kPa pressure difference can cause a 10 cm liquid level difference. Therefore, it is necessary to accurately identify the differences between operating parameters at the suction and discharge ends and respond promptly with dynamic correction. Thus, in this application, a control strategy compensates for the insufficient sensor accuracy, and an intelligent algorithm achieves precise control.

[0109] First, the current proportional relationship between the differences in operating parameters at the inhalation and exhaust ends is obtained. This proportional relationship has a magnifying effect on relative changes; even if the absolute changes in the differences between these parameters are small, the proportional relationship amplifies these minute changes because the ratio is relative, more sensitively reflecting subtle fluctuations in the system's operating state. This helps to promptly detect early anomalies or trend changes in non-equilibrium states. Second, the calculation of the difference parameters may also be affected by accuracy and drift. By calculating the ratio, the combined effects of accuracy and drift can be partially offset. Furthermore, by determining the fitted adjustment range corresponding to the current proportional relationship based on the functional relationship established by the proportional relationship and the opening adjustment range, the operating parameters can be smoothly estimated, avoiding over-adjustment and system oscillations.

[0110] Figure 6 This is a flowchart illustrating one embodiment of the processing device 30, using temperature as an example of an operating parameter. (T) s1 T represents the suction temperature of the first compressor 101. s2 T represents the suction temperature of the second compressor 102. d1 T represents the exhaust temperature of the first compressor 101. d2 This represents the exhaust temperature of the second compressor 102. The difference between the operating parameters at the suction end can be expressed as |T s1 -T s2The difference between the operating parameters at the discharge end can be expressed as |T|. d1 -T d2 |

[0111] In one or more embodiments of this application, the baseline equilibrium pressure estimation condition can be set as |T s1 -T s2 |≥A℃ and|T d1 -T d2 |≥A℃. A is a constant that can be pre-configured and stored. When |T| is satisfied... s1 -T s2 |≥A℃ and|T d1 -T d2 |≥A℃ indicates that the first gas-liquid separator 132 and the second gas-liquid separator 133 are in a non-equilibrium state.

[0112] If T is further satisfied s1 ≤T s2 -A℃, and T d1 ≥T d2 If the temperature is +A℃, then the first compressor 101 returns less oil and more liquid than the second compressor 102, the first gas-liquid separator 132 has a higher internal pressure than the second gas-liquid separator 133, and the liquid level of the first gas-liquid separator 132 is lower.

[0113] Calculate the ratio of the differences between the corresponding inhalation end operating parameters and the exhaust end operating parameters:

[0114]

[0115] Based on the function established according to the proportional relationship and the opening adjustment range, the fitting adjustment range ΔEV corresponding to m is determined.

[0116] The opening of the first electronic expansion valve 144 is adjusted to the minimum value. Every t minutes, the product of the opening of the previous second electronic expansion valve 147 and the fitted adjustment range is used as the actual opening, and the opening of the second electronic expansion valve 147 is gradually increased.

[0117] That is, the opening of the first electronic expansion valve 144 is adjusted to the minimum value. For example, the first electronic expansion valve 144 is closed. The opening of the second electronic expansion valve 147 can be expressed as PMV2(n)=PMV2(n-1)*ΔEV; where the initial opening of the second electromagnetic expansion valve satisfies PMV2(1)=PMVstart, and PMVstart is the opening pulse opening of the first electronic expansion valve 144, which is the minimum flow opening.

[0118] Figure 7 A flowchart of one embodiment of the processing device 30, if T is further satisfied s2 ≤T s1-A℃, and T d2 ≥T d1 If the temperature is +A℃, then the second compressor 102 returns less oil and more liquid than the first compressor 101, the internal pressure of the second gas-liquid separator 133 is higher than that of the first gas-liquid separator 132, and the liquid level of the second gas-liquid separator 133 is lower.

[0119] Calculate the ratio of the differences between the corresponding inhalation end operating parameters and the exhaust end operating parameters:

[0120]

[0121] Based on the function established according to the proportional relationship and the opening adjustment range, the fitting adjustment range ΔEV corresponding to m is determined.

[0122] The opening of the second electronic expansion valve 147 is adjusted to the minimum value. Every t minutes, the product of the opening of the previous electronic expansion valve and the fitted adjustment range is used as the actual opening, and the opening of the first electronic expansion valve 144 is gradually increased.

[0123] That is, the opening of the second electronic expansion valve 147 is adjusted to the minimum value. For example, the second electronic expansion valve 147 is closed. The opening of the first electronic expansion valve 144 can be expressed as PMV1(n)=PMV1(n-1)*ΔEV; where PMV1(1), that is, the initial opening of the first electromagnetic expansion valve satisfies PMV1(1)=PMVstart, and PMVstart is the opening pulse opening of the first electronic expansion valve 144, that is, the minimum flow opening.

[0124] In one or more embodiments of this application, ΔEV sets boundary value constraints, where ΔEV∈(100%, 165%).

[0125] In one or more embodiments of this application, the functional relationship established based on the proportional relationship and the opening adjustment range is obtained in the following way:

[0126] Under simulated conditions, the differences between operating parameters at the inhalation end and the differences between operating parameters at the exhaust end were collected.

[0127] Calculate the proportional relationship between the differences in operating parameters at the inhalation end and the differences in operating parameters at the exhaust end;

[0128] The opening of the electronic expansion valve corresponding to the one with the higher pressure among the multiple gas-liquid separators is reduced to the lower threshold.

[0129] In the preset data pool, a set of adjustment amplitude and adjustment frequency are randomly generated; based on the adjustment frequency, the set duration is divided into multiple continuous cycles, and the opening of the electronic expansion valve corresponding to the one with the lower pressure among the multiple gas-liquid separators is gradually increased by multiplying the opening of the electronic expansion valve of the previous cycle and the random adjustment amplitude as the actual opening.

[0130] At the end of the estimated set time, is the pressure difference between the multiple gas-liquid separators no longer in a non-equilibrium state?

[0131] If the state is no longer unbalanced, record the corresponding ratio and adjustment range as valid data points.

[0132] Repeat the above process to obtain multiple sets of data points corresponding to the proportional relationship and the opening adjustment range, and fit the data to obtain the functional relationship between the proportional relationship and the opening adjustment range.

[0133] The adjustment range and frequency in the preset data pool follow preset range constraints (e.g., the total adjustment range cannot exceed the maximum opening of the electronic expansion valve), step size constraints (e.g., the step size between adjacent adjustment ranges in the data pool cannot exceed a set value), and historical constraints (if the system performs better under one or more adjustment ranges and frequencies, it is preferable to increase their probability of occurrence in random generation), etc. The settings for the adjustment range and frequency in the preset data pool can be supplemented based on specific system and data requirements.

[0134] In one or more embodiments of this application, the functional relationship established based on the proportional relationship and the opening adjustment range is a polynomial fitting function. Figure 8 This is an example of a polynomial fitting function.

[0135] The amplification effect of ratios on relative changes can magnify small relative variations. This means that during the fitting process, it is easier to capture differences between operating parameters at the intake and exhaust ends, as well as nonlinear relationships between electronic expansion valves, which are the actuators. Simultaneously, the amplification effect of ratios on relative changes can help reduce the impact of data errors or noise, thereby improving the accuracy and reliability of the fitting. Therefore, a polynomial fitting function based on proportional relationships and opening adjustment amplitude can more accurately model and predict the behavior of air conditioning systems.

[0136] like Figure 9 As shown, in one or more embodiments of this application, the actuating component is a solenoid valve. Adjusting the operating parameters involves switching the solenoid valve on and off.

[0137] When adjusting operating parameters, the following steps are included:

[0138] Acquire the differences between the operating parameters at the inhalation end and the operating parameters at the exhalation end;

[0139] Based on the differences between the operating parameters at the inhalation end and the operating parameters at the discharge end, according to the set intervention cycle, the solenoid valve corresponding to the one with the higher pressure among the multiple gas-liquid separators is closed, and the solenoid valve corresponding to the one with the lower pressure among the multiple gas-liquid separators is opened.

[0140] like Figure 9 As shown, the outdoor module 10 includes a first regulating branch 155 and a second regulating branch 159. The first regulating branch 155 is located between the first outlet pipe 149 and the first drain pipe 129, and the second regulating branch 159 is located between the second outlet pipe 150 and the second drain pipe 130. A first solenoid valve 157 is installed on the first regulating branch 155, and a second solenoid valve 161 is installed on the second regulating branch 159. The first solenoid valve 157 is connected in series with the filter 156 and the first regulating capillary tube 158, and the second solenoid valve 161 is connected in series with the filter 160 and the second regulating capillary tube 162.

[0141] Figure 10 This is a flowchart of one embodiment of the processing device 30. In one or more embodiments of this application, the reference equilibrium pressure estimation condition can be set as |T s1 -T s2 |≥A℃ and|T d1 -T d2 |≥A℃.

[0142] If T is further satisfied s1 ≤T s2 -A℃, and T d1 ≥T d2 If the temperature is +A℃, then the first compressor 101 returns less oil and more liquid than the second compressor 102. At the same time, the first gas-liquid separator 132 and the second gas-liquid separator 133 are in an unbalanced state, and the internal pressure of the first gas-liquid separator 132 is higher than that of the second gas-liquid separator 133, and the liquid level of the first gas-liquid separator 132 is lower.

[0143] In each adjustment cycle, the first solenoid valve 157 is closed and the second solenoid valve 161 is opened.

[0144] Figure 11 A flowchart of one embodiment of the processing device 30, if T is further satisfied s2 ≤T s1 -A℃, and T d2 ≥T d1If the temperature is +A℃, then the second compressor 102 returns less oil and more liquid than the first compressor 101. At the same time, the first gas-liquid separator 132 and the second gas-liquid separator 133 are in an unbalanced state, and the internal pressure of the second gas-liquid separator 133 is higher than that of the first gas-liquid separator 132, and the liquid level of the second gas-liquid separator 133 is lower.

[0145] During each adjustment cycle, the first solenoid valve 157 is opened and the second solenoid valve 161 is closed.

[0146] In one or more embodiments of this application, the actuating components are a plurality of compressors. The estimation unit, based on the current operating frequency of the compressors, reduces the pressure difference between the plurality of gas-liquid separators by changing the current operating frequency of the compressors.

[0147] like Figure 12 As shown, the outdoor module 10 has an regulating branch 151. The regulating branch 151 is located between the junction pipe 142 and the distribution pipe 127 after the first outlet pipe and the second outlet pipe merge. A solenoid valve 153 is installed on the regulating branch 151, and the solenoid valve 153 is connected in series with the filter 152 and the regulating capillary tube 154.

[0148] Figure 13 This is a flowchart of one embodiment of the processing device 30. In one or more embodiments of this application, the reference equilibrium pressure estimation condition can be set as |T s1 -T s2 |≥A℃ and|T d1 -T d2 |≥A℃.

[0149] If T is further satisfied s1 ≤T s2 -A℃, and T d1 ≥T d2 If the temperature is +A℃, then the first compressor 101 returns less oil and more liquid than the second compressor 102. At the same time, the first gas-liquid separator 132 and the second gas-liquid separator 133 are in an unbalanced state, and the internal pressure of the first gas-liquid separator 132 is higher than that of the second gas-liquid separator 133, and the liquid level of the first gas-liquid separator 132 is lower.

[0150] In each adjustment cycle, control is executed to increase the frequency of the first compressor 101 until the frequency of the first compressor 101 reaches the upper frequency threshold; control is executed to decrease the frequency of the second compressor 102 until the frequency of the second compressor 102 reaches the lower frequency threshold or is no longer in an unbalanced state.

[0151] Figure 14 A flowchart of one embodiment of the processing device 30, if T is further satisfied s2 ≤T s1-A℃, and T d2 ≥T d1 If the temperature is +A℃, then the second compressor 102 returns less oil and more liquid than the first compressor 101. At the same time, the first gas-liquid separator 132 and the second gas-liquid separator 133 are in an unbalanced state, and the internal pressure of the second gas-liquid separator 133 is higher than that of the first gas-liquid separator 132, and the liquid level of the second gas-liquid separator 133 is lower.

[0152] In each adjustment cycle, control is executed to increase the frequency of the second compressor 102 until the frequency of the second compressor 102 reaches the upper frequency threshold; control is executed to decrease the frequency of the first compressor 101 until the frequency of the first compressor 101 reaches the lower frequency threshold or is no longer in an unbalanced state.

[0153] Within each adjustment cycle, the compressor frequency is adjusted by the same amount. For example, the adjustment amount is 2Hz.

[0154] The normal operating parameters are generated according to the preset algorithms in the existing technology. For example, the electronic expansion valve and solenoid valve on the regulating branch can be controlled according to the pressure relief requirements, and the compressor operating frequency is controlled normally.

[0155] like Figure 15 As shown, in one or more embodiments of this application, the estimation unit is further configured to, in cooling mode, estimate corresponding regulating operating parameters based on the differences between the operating parameters at the suction end, the differences between the operating parameters at the discharge end, and the reference equilibrium pressure estimation condition, according to the normal operating parameters of the electrically driven actuator in the indoor module 20. When the actuator in the indoor module 20 operates according to the regulating operating parameters, the refrigerant flow rate in the distribution pipeline 127 decreases, and the pressure difference between the plurality of gas-liquid separators decreases.

[0156] In this embodiment, by increasing the superheat of the indoor module 20, the flow rate of the evaporating refrigerant is relatively reduced, thereby improving the evaporation effect; further reducing the refrigerant flow rate in the distribution pipeline 127 increases the concentration of lubricating oil in the two gas-liquid separators, so that the oil-rich layer at the bottom of the higher-pressure gas-liquid separator is not continuously diluted, thereby allowing the pressure in both to reach a balanced state after adjustment.

[0157] In one or more embodiments of this application, the actuating component is an indoor throttling element 119. Based on the current opening degree of the indoor throttling element 119, the estimation unit reduces the refrigerant flow rate in the distribution line 127 and decreases the pressure difference between the plurality of gas-liquid separators by changing the current opening degree of the indoor throttling element 119. The indoor throttling element 119 is an indoor electronic expansion valve.

[0158] In one or more embodiments of this application, the estimation unit reduces the refrigerant flow rate in the distribution line 127 and reduces the pressure difference between the plurality of gas-liquid separators by changing the current opening degree of the indoor throttling element 119, including:

[0159] Obtain the current proportional relationship between the differences between the operating parameters at the inhalation end and the differences between the operating parameters at the exhaust end;

[0160] Based on the functional relationship established by the proportional relationship and the opening adjustment range, the fitting adjustment range corresponding to the current proportional relationship is determined; by repeatedly using the product of the opening of the previous indoor throttling element 119 and the fitting adjustment range as the actual opening, the opening of the indoor throttling element 119 is gradually reduced until the opening of the indoor throttling element 119 reaches the minimum opening, or the pressure difference between the multiple gas-liquid separators is no longer in a non-equilibrium state; wherein the initial opening of the indoor throttling element 119 is the minimum flow opening.

[0161] In one or more embodiments of this application, the functional relationship based on the proportional relationship and the opening adjustment range is obtained in the following way:

[0162] Under simulated conditions, the differences between operating parameters at the inhalation end and the differences between operating parameters at the exhaust end were collected.

[0163] Calculate the proportional relationship between the differences in operating parameters at the inhalation end and the differences in operating parameters at the exhaust end;

[0164] In the preset data pool, a set of adjustment amplitude and adjustment frequency are randomly generated; based on the adjustment frequency, the set duration is divided into multiple continuous cycles, and the opening of the indoor throttling element 119 is gradually reduced by using the product of the opening degree of the indoor throttling element 119 in the previous cycle and the random adjustment amplitude as the actual opening degree.

[0165] At the end of the estimated set time, is the pressure difference between the multiple gas-liquid separators no longer in a non-equilibrium state?

[0166] If the system is no longer in a state of disequilibrium, the corresponding ratio and random adjustment amplitude are recorded as valid data points.

[0167] Repeat the above process to fit and obtain the functional relationship between the proportional relationship and the opening adjustment range.

[0168] In one or more embodiments of this application, the functional relationship established based on the proportional relationship and the opening adjustment range is a polynomial fitting function, such as... Figure 16 As shown.

[0169] In one or more embodiments of this application, the actuating component further includes a plurality of compressors, and the control effect is achieved through the coordinated operation of the compressors and the indoor throttling element 119. The estimation unit is configured to continuously change the current opening degree of the indoor throttling element 119 several times, thereby reducing the refrigerant flow rate in the distribution pipeline 127 and reducing the pressure difference between the plurality of gas-liquid separators; if the pressure difference between the plurality of gas-liquid separators is still in an unbalanced state after continuously changing the current opening degree of the indoor throttling element 119 several times, then the pressure difference between the plurality of gas-liquid separators is reduced by changing the current operating frequency of the compressors.

[0170] Figure 17 This is a flowchart of one embodiment of the processing device 30. In one or more embodiments of this application, the reference equilibrium pressure estimation condition can be set as |T s1 -T s2 |≥A℃ and|T d1 -T d2 |≥A℃. A is a constant that can be pre-configured and stored. When the above equation is satisfied, the first gas-liquid separator 132 and the second gas-liquid separator 133 are in a non-equilibrium state.

[0171] Calculate the ratio of the differences between the corresponding inhalation end operating parameters and the exhaust end operating parameters:

[0172]

[0173] Based on the function established according to the proportional relationship and the opening adjustment range, the fitting adjustment range ΔEV corresponding to m is determined.

[0174] Every t minutes, the opening of the indoor throttling element 119 is gradually reduced by using the product of the previous indoor throttling element's opening degree and the fitted adjustment range as the actual opening degree. The opening degree of the indoor throttling element 119 can be expressed as EVI(n) = EVI(n-1) * ΔEV, until the opening degree of the indoor throttling element 119 reaches its minimum opening degree, or the pressure difference between the multiple gas-liquid separators is no longer in a non-equilibrium state. ΔEV ∈ [30%, 100%).

[0175] After several consecutive adjustments, if the pressure difference between the multiple gas-liquid separators remains unbalanced, the frequency of the first compressor 101 and the second compressor 102 will be reduced in each adjustment cycle until the unbalanced state is resolved. If the pressure difference between the multiple gas-liquid separators remains unbalanced after several consecutive adjustments, the air conditioning system will be shut down.

[0176] Within each adjustment cycle, the compressor frequency is adjusted by the same amount. For example, the adjustment amount is 3Hz.

[0177] like Figure 18 As shown, in one or more embodiments of this application, the estimation unit is further configured to, in heating mode, estimate corresponding regulating operating parameters based on the differences between the operating parameters at the suction end, the differences between the operating parameters at the discharge end, and the reference equilibrium pressure estimation condition, according to the normal operating parameters of the electrically driven actuator in the outdoor module. When the actuator in the outdoor module operates according to the regulating operating parameters, the refrigerant flow rate in the distribution pipeline 127 decreases, and the pressure difference between the plurality of gas-liquid separators decreases.

[0178] In this embodiment, by increasing the superheat of the outdoor module, the flow rate of the evaporating refrigerant is relatively reduced, thereby improving the evaporation effect. Furthermore, by reducing the refrigerant flow rate in the distribution pipeline 127, the concentration of lubricating oil in the two gas-liquid separators is increased, so that the oil-rich layer at the bottom of the higher-pressure gas-liquid separator is not continuously diluted, thereby allowing the pressure in both to reach a balanced state after adjustment.

[0179] In one or more embodiments of this application, the actuating component is an outdoor fan. The estimation unit, based on the current speed of the outdoor fan, reduces the refrigerant flow rate in the distribution pipeline 127 by changing the current speed of the outdoor fan, thereby reducing the pressure difference between the plurality of gas-liquid separators.

[0180] In one or more embodiments of this application, the actuating component is an outdoor throttling element. Based on the current opening degree of the outdoor throttling element, the estimation unit reduces the refrigerant flow rate in the distribution pipeline 127 by changing the current opening degree of the outdoor throttling element, thereby reducing the pressure difference between the plurality of gas-liquid separators. The outdoor throttling element is an indoor electronic expansion valve.

[0181] In one or more embodiments of this application, the estimation unit reduces the refrigerant flow rate in the distribution pipeline 127 and reduces the pressure difference between the plurality of gas-liquid separators by changing the current opening degree of the outdoor throttling element, including:

[0182] Obtain the current proportional relationship between the differences between the operating parameters at the inhalation end and the differences between the operating parameters at the exhaust end;

[0183] Based on the functional relationship established by the proportional relationship and the opening adjustment range, the fitting adjustment range corresponding to the current proportional relationship is determined; by repeatedly using the product of the opening of the previous outdoor throttling element and the fitting adjustment range as the actual opening, the opening of the outdoor throttling element 116 is gradually reduced until the opening of the outdoor throttling element 116 reaches the minimum opening, or the pressure difference between the multiple gas-liquid separators is no longer in a non-equilibrium state; wherein the initial opening of the outdoor throttling element 116 is the minimum flow opening.

[0184] In one or more embodiments of this application, the functional relationship based on the proportional relationship and the opening adjustment range is obtained in the following way:

[0185] Under simulated conditions, the differences between operating parameters at the inhalation end and the differences between operating parameters at the exhaust end were collected.

[0186] Calculate the proportional relationship between the differences in operating parameters at the inhalation end and the differences in operating parameters at the exhaust end;

[0187] In the preset data pool, a set of adjustment amplitude and adjustment frequency are randomly generated; based on the adjustment frequency, the set duration is divided into multiple continuous cycles, and the opening of the outdoor throttling element 116 is gradually reduced by using the product of the opening degree of the outdoor throttling element 116 in the previous cycle and the random adjustment amplitude as the actual opening degree.

[0188] At the end of the estimated set time, is the pressure difference between the multiple gas-liquid separators no longer in a non-equilibrium state?

[0189] If the system is no longer in a state of disequilibrium, the corresponding ratio and random adjustment amplitude are recorded as valid data points.

[0190] Repeat the above process to obtain multiple valid data points, and fit the functional relationship between the proportional relationship and the opening adjustment range.

[0191] In one or more embodiments of this application, the functional relationship established based on the proportional relationship and the opening adjustment range is a polynomial fitting function.

[0192] In one or more embodiments of this application, the actuating components further include a plurality of compressors. The estimation unit is configured to continuously and repeatedly reduce the refrigerant flow rate in the distribution line 127 and the pressure difference between the plurality of gas-liquid separators by changing the current opening degree of the outdoor throttling element 116; if the pressure difference between the plurality of gas-liquid separators is still in an unbalanced state after continuously and repeatedly changing the current opening degree of the outdoor throttling element 116, then the pressure difference between the plurality of gas-liquid separators is reduced by changing the current operating frequency of the compressors.

[0193] Figure 19 This is a flowchart of one embodiment of the processing device 30. In one or more embodiments of this application, the reference equilibrium pressure estimation condition can be set as |T s1 -T s2 |≥A℃ and|T d1 -T d2 |≥A℃. A is a constant that can be pre-configured and stored. When the above equation is satisfied, the first gas-liquid separator 132 and the second gas-liquid separator 133 are in a non-equilibrium state.

[0194] Calculate the ratio of the differences between the corresponding inhalation end operating parameters and the exhaust end operating parameters:

[0195]

[0196] During each adjustment cycle, the outdoor fan speed is increased until the outdoor fan reaches its maximum speed or is no longer in an unbalanced state.

[0197] Within each adjustment cycle, the adjustment range of the fan speed is the same. For example, the adjustment range is 5% of the maximum speed.

[0198] After several consecutive fan speed adjustments, if the pressure difference between the multiple gas-liquid separators is still in an unbalanced state, the fitted adjustment range ΔEV corresponding to m is determined based on the function established by the proportional relationship and the opening adjustment range.

[0199] Every t minutes, the actual opening degree of the previous outdoor throttling element 116 is taken as the product of the previous opening degree and the fitted adjustment range. The opening degree of the outdoor throttling element 116 is gradually reduced. The opening degree of the outdoor throttling element 116 can be expressed as EVO(n) = EVO(n-1) * ΔEV, until the opening degree of the outdoor throttling element 116 reaches the minimum opening degree, or the pressure difference between the multiple gas-liquid separators is no longer in a non-equilibrium state. ΔEV∈[30%, 100%).

[0200] After several consecutive adjustments, if the pressure difference between the multiple gas-liquid separators remains unbalanced, the frequencies of the first compressor 101 and the second compressor 102 are reduced in each adjustment cycle until the unbalanced state is resolved. If, after several consecutive adjustments, the pressure difference between the multiple gas-liquid separators remains unbalanced, the air conditioning system is shut down. The reduced frequency is a set value, for example, 3Hz.

[0201] The standard operating parameters are generated based on preset algorithms in existing technologies, including the opening degree of the indoor electronic expansion valve, the opening degree of the outdoor electronic expansion valve, and the compressor operating frequency.

[0202] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0203] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. Air conditioning system, including: Outdoor module, which has: Multiple compressors; Switching valve; Multiple oil separators are respectively installed at the discharge end of the compressor; A plurality of gas-liquid separators are respectively installed at the suction end of the compressor, and a liquid equalization pipe is provided between the gas-liquid separators; and Distribution pipelines are fluidly connected to multiple gas-liquid separators; and Indoor modules; Its characteristic is that it further includes: The processing device includes: The data acquisition unit is configured to collect operating parameters from the inlet and outlet ends of multiple compressors. The calculation unit is configured to calculate the differences between the operating parameters at the suction end of a plurality of compressors and the differences between the operating parameters at the discharge end of a plurality of compressors. and The estimation unit is configured to, in cooling mode, estimate the corresponding adjustment operating parameters based on the differences between the operating parameters at the suction end, the differences between the operating parameters at the discharge end, and the reference balance pressure estimation condition, according to the normal operating parameters of the electrically driven actuator in the indoor module. The reference balance pressure estimation condition is used to determine whether the pressure difference between the plurality of gas-liquid separators is in an unbalanced state; and when the actuator in the indoor module operates according to the adjusted operating parameters, the refrigerant flow in the distribution pipeline decreases, and the pressure difference between the plurality of gas-liquid separators decreases.

2. The air conditioning system according to claim 1, characterized in that: The actuating component is an indoor throttling element; the estimating unit, based on the current opening degree of the indoor throttling element, reduces the refrigerant flow rate in the distribution pipeline and reduces the pressure difference between the plurality of gas-liquid separators by changing the current opening degree of the indoor throttling element.

3. The air conditioning system according to claim 2, characterized in that: The estimation unit, based on the current opening degree of the indoor throttling element, reduces the refrigerant flow rate in the distribution pipeline and decreases the pressure difference between the plurality of gas-liquid separators by changing the current opening degree of the indoor throttling element, including: Obtain the current proportional relationship between the differences between the operating parameters at the inhalation end and the differences between the operating parameters at the exhaust end; Based on the functional relationship established by the proportional relationship and the opening adjustment range, the fitting adjustment range corresponding to the current proportional relationship is determined; by repeatedly using the product of the opening of the previous indoor throttling element and the fitting adjustment range as the actual opening, the opening of the indoor throttling element is gradually reduced until the opening of the indoor throttling element reaches the minimum opening, or the pressure difference between the multiple gas-liquid separators is no longer in a non-equilibrium state.

4. The air conditioning system according to claim 3, characterized in that: The functional relationship established based on the proportional relationship and the opening adjustment range is obtained in the following way: Under simulated conditions, the differences between operating parameters at the inhalation end and the differences between operating parameters at the exhaust end were collected. Calculate the proportional relationship between the differences in operating parameters at the inhalation end and the differences in operating parameters at the exhaust end; In the preset data pool, a set of adjustment amplitude and adjustment frequency are randomly generated; based on the adjustment frequency, the set duration is divided into multiple continuous cycles, and the opening of the indoor throttling element is gradually reduced by using the product of the opening degree of the indoor throttling element in the previous cycle and the random adjustment amplitude as the actual opening degree. At the end of the estimated set time, is the pressure difference between the multiple gas-liquid separators no longer in a non-equilibrium state? If the system is no longer in a state of disequilibrium, the corresponding ratio and random adjustment amplitude are recorded as valid data points. Multiple valid data points are obtained, and the functional relationship between the proportional relationship and the opening adjustment range is fitted.

5. The air conditioning system according to claim 4, characterized in that: The estimation unit is further configured to estimate the regulating operating parameters by changing the current operating frequency of the compressors based on the current operating frequency of the plurality of compressors, thereby reducing the refrigerant flow rate in the distribution pipeline and reducing the pressure difference between the plurality of gas-liquid separators.

6. Air conditioning system, including: Outdoor module, which has: Multiple compressors; Switching valve; Multiple oil separators are respectively installed at the discharge end of the compressor; A plurality of gas-liquid separators are respectively installed at the suction end of the compressor, and a liquid equalization pipe is provided between the gas-liquid separators; and Distribution pipelines are fluidly connected to multiple gas-liquid separators; Its characteristic is that it further includes: The processing device includes: The data acquisition unit is configured to collect operating parameters from the inlet and outlet ends of multiple compressors. The calculation unit is configured to calculate the differences between the operating parameters at the suction end of a plurality of compressors and the differences between the operating parameters at the discharge end of a plurality of compressors. and The estimation unit is configured to, in heating mode, estimate the corresponding regulating operating parameters based on the differences between the operating parameters at the inlet end, the differences between the operating parameters at the outlet end, and the reference equilibrium pressure estimation condition, according to the normal operating parameters of the electrically driven actuator in the outdoor module. The reference balance pressure estimation condition is used to determine whether the pressure difference between the plurality of gas-liquid separators is in an unbalanced state; and when the actuator in the outdoor module operates according to the adjusted operating parameters, the refrigerant flow in the distribution pipeline decreases, and the pressure difference between the plurality of gas-liquid separators decreases.

7. The air conditioning system according to claim 6, characterized in that: The actuator includes an outdoor fan; the estimation unit estimates the regulating operating parameters by changing the current speed of the outdoor fan based on the current speed of the outdoor fan, thereby reducing the refrigerant flow rate in the distribution pipeline and reducing the pressure difference between the plurality of gas-liquid separators.

8. The air conditioning system according to claim 7, characterized in that: The actuator also includes an outdoor throttling element; the estimation unit estimates the regulating operating parameters by changing the current opening of the outdoor throttling element based on the current opening of the outdoor throttling element, thereby reducing the refrigerant flow rate in the distribution pipeline and reducing the pressure difference between the plurality of gas-liquid separators.

9. The air conditioning system according to claim 8, characterized in that: The estimation unit, based on the current opening degree of the outdoor throttling element, reduces the refrigerant flow rate in the distribution pipeline and decreases the pressure difference between the plurality of gas-liquid separators by changing the current opening degree of the outdoor throttling element, including: Obtain the current proportional relationship between the differences between the operating parameters at the inhalation end and the differences between the operating parameters at the exhaust end; Based on the functional relationship established by the proportional relationship and the opening adjustment range, the fitting adjustment range corresponding to the current proportional relationship is determined; by repeatedly using the product of the opening of the previous outdoor throttling element and the fitting adjustment range as the actual opening, the opening of the outdoor throttling element is gradually reduced until the opening of the outdoor throttling element reaches the minimum opening, or the pressure difference between the multiple gas-liquid separators is no longer in a non-equilibrium state.

10. The air conditioning system according to claim 6, characterized in that: The actuator also includes a plurality of compressors; the estimation unit estimates the adjustment operating parameters by changing the current operating frequency of the compressors based on the current operating frequency of the plurality of compressors, thereby reducing the refrigerant flow in the distribution pipeline and reducing the pressure difference between the plurality of gas-liquid separators.

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