Refrigerator

Abstract

The present disclosure belongs to the technical field of refrigerators, and provides a refrigerator, a variable frequency compressor, a flow regulating valve, a condensing fan and a controller are arranged in the cabinet of the refrigerator, the controller is configured to determine a basic opening degree of the flow regulating valve according to the running speed of the variable frequency compressor and the refrigeration running mode of the refrigerator; determine a first opening degree constraint value and a second opening degree constraint value; the first opening degree constraint value represents the maximum value between the first minimum opening degree determined by the suction side refrigerant pressure of the variable frequency compressor and the second minimum opening degree determined based on the refrigerant supercooling degree at the inlet of the flow regulating valve, and the second opening degree constraint value represents the maximum opening degree determined based on the refrigerant supercooling degree at the inlet of the flow regulating valve; and then if the first opening degree constraint value is greater than the second opening degree constraint value, the flow regulating valve is controlled to adjust the refrigerant flow based on a safety opening degree, so that the performance potential of the variable frequency compressor can be fully released under the premise of ensuring the operation reliability of the refrigeration system.

Description

Technical Field

[0001] This disclosure pertains to the field of refrigerator technology, and more specifically, relates to a refrigerator. Background Technology

[0002] Currently, in refrigerator refrigeration systems equipped with wide-speed inverter compressors, it is difficult to precisely match the refrigerant flow rate with changes in speed. Especially under high-speed, high-load temperature-pushing conditions, a coupling contradiction can easily occur between excessively low suction pressure (triggering low-pressure protection) and insufficient subcooling of the refrigerant before the valve (leading to the risk of flashover).

[0003] The lack of an effective conflict arbitration mechanism in existing technologies often forces controllers to limit compressor speed or reduce valve opening, failing to fully utilize the energy-saving potential and refrigeration performance of wide-speed inverter compressors over a wide speed range, and resulting in poor operational stability of the refrigerator refrigeration system. Summary of the Invention

[0004] The purpose of this disclosure is to provide a refrigerator that addresses the technical problem in the related art of not being able to fully utilize the energy-saving potential and refrigeration performance of a wide-speed inverter compressor over a wide speed range.

[0005] To achieve the above objectives, in a first aspect, embodiments of this disclosure provide a refrigerator, which includes a cabinet, and a variable frequency compressor, a flow regulating valve, a condenser fan, and a controller disposed within the cabinet. The controller is electrically connected to the variable frequency compressor, the flow regulating valve, and the condenser fan, respectively, and is configured to: Based on the operating speed of the variable frequency compressor and the refrigeration operation mode of the refrigerator, consult the pre-stored speed and opening degree mapping table to determine the basic opening degree of the flow regulating valve; Determine a first opening constraint value and a second opening constraint value, wherein the first opening constraint value represents the maximum value between a first minimum opening determined by the refrigerant pressure on the suction side of the variable frequency compressor and a second minimum opening determined based on the refrigerant subcooling at the inlet of the flow control valve, and the second opening constraint value represents the maximum opening determined based on the refrigerant subcooling at the inlet of the flow control valve. If the first opening constraint value is greater than the second opening constraint value, the control flow regulating valve adjusts the refrigerant flow based on the safe opening value; wherein, the safe opening value is a pre-calibrated fixed opening value, which is determined through prototype testing; or, the safe opening value is the target opening value output in the most recent control cycle before the first opening constraint value is greater than the second opening constraint value; or, the safe opening value is the average of the first opening constraint value and the second opening constraint value.

[0006] The beneficial effects of the embodiments disclosed herein compared to the prior art are as follows: By querying a pre-stored speed-to-opening mapping table based on the operating speed and refrigeration mode of the variable frequency compressor, the basic opening of the flow regulating valve is determined, achieving feedforward matching of refrigerant flow rate with compressor gas delivery. By constructing a first minimum opening based on the suction-side refrigerant pressure and a second minimum opening based on the refrigerant subcooling before the valve, and taking the maximum value of these two as the first opening constraint value, and constructing a maximum opening based on the refrigerant subcooling before the valve as the second opening constraint value, a dual dynamic definition of the low-pressure safety boundary and flashover safety boundary of the refrigeration system is achieved.

[0007] Furthermore, when the first opening constraint value is greater than the second opening constraint value, the refrigeration system is determined to enter a conflict state between low-pressure demand and flashover prevention. To address this, this solution controls the flow regulating valve to adjust the refrigerant flow based on a preset safe opening value. This safe opening value can be a pre-calibrated fixed value, the most recent effective opening value before the conflict, or the average of the constraint values. The aim is to maintain the basic operation of the refrigeration system during the conflict and avoid the inverter compressor from shutting down.

[0008] Through the aforementioned conflict arbitration mechanism, this disclosure is particularly effective in resolving the contradiction between low-pressure protection and flashover prevention under extreme operating conditions (such as high-temperature environments and ultra-high-speed temperature pulling), thereby freeing the variable frequency compressor from the constraints of high-speed operation and fully releasing the potential of the wide-speed variable frequency compressor in terms of refrigeration performance. At the same time, by maintaining the safe opening degree, it buys time for subsequent coordinated adjustments (such as condenser fan speed increase), ensuring the stable operation of the wide-speed variable frequency compressor across the entire speed range. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a schematic block diagram of the structure of a refrigerator provided in an embodiment of this disclosure; Figure 2 This is a schematic flowchart of a refrigerator control method provided in an embodiment of this disclosure; Figure 3 This is a schematic flowchart of a refrigerator control method provided in an embodiment of this disclosure; Figure 4 This is a schematic flowchart of a refrigerator control method provided in an embodiment of this disclosure; Figure 5 This is a schematic flowchart of a refrigerator control method provided in an embodiment of this disclosure; Figure 6This is a schematic flowchart of a refrigerator control method provided in an embodiment of this disclosure; Figure 7 This is a schematic flowchart of a refrigerator control method provided in an embodiment of this disclosure; Figure 8 This is a schematic diagram of the structure of a refrigerator control device provided in an embodiment of this disclosure; Figure 9 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this disclosure. Detailed Implementation

[0011] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, so as to provide a thorough understanding of the embodiments of this disclosure. However, those skilled in the art will understand that this disclosure may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this disclosure with unnecessary detail.

[0012] It should be understood that, when used in this disclosure and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0013] It should also be understood that, in the description of this disclosure, unless otherwise stated, the " / " used in this specification and the appended claims indicates that the related objects are in an "or" relationship. For example, A / B can mean A or B. The "and / or" in this disclosure is merely a description of the relationship between the related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. Furthermore, in the description of this disclosure, unless otherwise stated, "multiple" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0014] Furthermore, to facilitate a clear description of the technical solutions of the embodiments of this disclosure, the terms "first" and "second" are used in the embodiments of this disclosure to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, but are only used for distinguishing descriptions, and the terms "first" and "second" are not necessarily different, nor should they be construed as indicating or implying relative importance.

[0015] As used in this disclosure and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if [the described condition or event] is detected" may be interpreted, depending on the context, as "once determined," "in response to determination," "once [the described condition or event] is detected," or "in response to detection of [the described condition or event]."

[0016] References to "one embodiment" or "some embodiments" as described in this disclosure mean that one or more embodiments of this disclosure include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including, but not limited to," unless otherwise specifically emphasized.

[0017] In the field of refrigerator refrigeration technology, variable frequency compressors are widely used because they can dynamically adjust their operating speed according to the system load. Among them, wide-speed variable frequency compressors can cover a wide range of speeds from low to high. Theoretically, they can operate at a lower speed under low-load steady-state conditions to reduce energy consumption, and operate at a higher speed under high-load temperature-pushing conditions to increase cooling capacity.

[0018] However, the throttling element in refrigerator refrigeration systems has long been a capillary tube with fixed geometric parameters. Once the inner diameter and length of the capillary tube are determined, its refrigerant flow rate remains essentially constant under a specific pressure difference, and it can only be adapted to a specific design speed point. When the actual operating speed of the compressor deviates from this design speed point, a mismatch occurs between the refrigerant circulation volume and the compressor's gas delivery volume.

[0019] More importantly, under wide-speed operation, especially high-speed, high-load, and temperature-boosting conditions, a coupling contradiction easily arises between excessively low suction pressure (triggering low-pressure protection) and insufficient subcooling of the refrigerant before the valve (leading to flashover risk). For example, under high-speed operation, the compressor's gas delivery volume increases significantly, and the suction pressure drops rapidly. The refrigeration system needs to open the valve wider to increase the liquid supply and maintain the suction pressure. However, at the same time, when the condensing load increases at high speed or the ambient temperature is high, the subcooling of the refrigerant before the valve may decrease sharply. The refrigeration system needs to close the valve narrower to increase the throttling pressure drop and prevent flashover. This direct conflict between "low-pressure demand" and "flashover prevention" is difficult for existing control logic to resolve.

[0020] To address the aforementioned matching problem, several known solutions have been proposed in the industry, such as using closed-loop control with electronic expansion valves, parallel switching of multiple capillary tubes, locking the compressor speed range, or establishing a simple lookup table feedforward relationship between speed and valve opening. However, these solutions either suffer from high hardware costs, significant system modifications, discrete flow regulation, and sacrifice of wide speed range advantages, or they are open-loop controls unable to cope with actual disturbances. Furthermore, none of them have effectively established a predictive and control mechanism for low-pressure risks and changes in the refrigerant state before the valve, and they lack an effective arbitration strategy when these two factors conflict.

[0021] In summary, existing refrigerator refrigeration system control schemes struggle to achieve continuous, adaptive, and dynamic adjustment of refrigerant flow while considering system safety boundaries across a wide speed range. In particular, they lack effective fallback and recovery measures when facing safety boundary conflicts, which limits the energy-saving potential and refrigeration performance of wide-speed inverter compressors in practical applications, preventing them from being fully realized.

[0022] To address the aforementioned technical problems, this disclosure provides an example of a refrigerator, please refer to... Figure 1 As shown, Figure 1 The diagram shows a schematic structural diagram of a refrigerator provided in this disclosure, which is provided as an example and not a limitation. The refrigerator includes a cabinet 100, and a variable frequency compressor 101, a flow regulating valve 102, a condenser fan 103, and a controller 104 disposed within the cabinet 100. The controller 104 is electrically connected to the variable frequency compressor 101, the flow regulating valve 102, and the condenser fan 103 respectively (the connections between some components and the controller are not shown). The controller is configured to perform actions such as... Figure 2 The flowchart of the refrigerator control method shown is as follows: S201. Based on the operating speed of the variable frequency compressor and the refrigeration operation mode of the refrigerator, query the pre-stored speed and opening degree mapping table to determine the basic opening degree of the flow regulating valve.

[0023] S202. Determine the first opening constraint value and the second opening constraint value.

[0024] The first opening constraint value represents the maximum value between the first minimum opening determined by the refrigerant pressure on the suction side of the variable frequency compressor and the second minimum opening determined based on the refrigerant subcooling at the inlet of the flow regulating valve. The second opening constraint value represents the maximum opening determined based on the refrigerant subcooling at the inlet of the flow regulating valve.

[0025] S203. If the first opening constraint value is greater than the second opening constraint value, the flow regulating valve is controlled to adjust the refrigerant flow based on the safe opening value.

[0026] Among them, the safe opening degree is a pre-calibrated fixed opening degree value, which is determined through prototype testing; or, the safe opening degree is the target opening degree output in the most recent control cycle before the first opening degree constraint value is greater than the second opening degree constraint value; or, the safe opening degree is the average value of the first opening degree constraint value and the second opening degree constraint value.

[0027] In one embodiment, the refrigerator provided in this embodiment may be, but is not limited to, a frost-free multi-compartment refrigerator with a refrigerator compartment and a freezer compartment for storing food. The inverter compressor may specifically be a wide-speed inverter compressor, which can be connected to the refrigeration circuit and configured to compress the refrigerant and drive its circulation. The refrigerator's refrigeration system can use an inverter compressor as a power source, and the operating speed of the inverter compressor can vary within a wide speed range, for example, continuously adjustable between 800 rpm and 6300 rpm. This wide-speed design allows the refrigerator to increase its cooling capacity under high load conditions by increasing the speed, and to achieve energy-saving operation under low load steady-state conditions by reducing the speed.

[0028] In some embodiments, a flow regulating valve may be connected in series in the main refrigeration circuit of the refrigerator. The flow regulating valve can receive opening commands from the controller to regulate the refrigerant flow through the main refrigeration circuit. A condenser fan may be located near the condenser and configured to accelerate airflow around the condenser, thereby enhancing the condenser's heat dissipation and heat exchange capacity and increasing the subcooling of the refrigerant after it exits the condenser. The controller may be electrically connected to the inverter compressor, the condenser fan, and the flow regulating valve, and is configured to execute the refrigerator control method provided in this disclosure, namely, the refrigerant flow adaptive control method.

[0029] The controller can obtain the operating speed of the inverter compressor and the refrigeration operation mode of the refrigerator, and determine the basic opening degree, i.e., the initial opening degree, of the flow regulating valve based on the operating speed and refrigeration operation mode. For example, the controller queries a pre-stored speed-to-opening degree mapping table based on the operating speed and refrigeration operation mode to obtain the basic opening degree of the flow regulating valve. For example, the refrigeration operation mode may include a single refrigeration mode, a single freezing mode, and a dual-path refrigeration and freezing operation mode, and the pre-stored speed-to-opening degree mapping table may include independent mapping sub-tables corresponding to each of these modes.

[0030] By querying the mapping sub-table based on the operating speed and refrigeration mode of the variable frequency compressor, the basic opening degree of the flow regulating valve can be determined, enabling feedforward matching of refrigerant flow rate with the compressor's gas delivery volume. Under high-speed, high-temperature conditions, a larger basic opening degree provides sufficient refrigerant supply to the compressor's high gas delivery volume, preventing insufficient refrigerant supply from deteriorating the refrigeration capacity and thus fully utilizing the rapid refrigeration performance of the wide-speed variable frequency compressor under high loads. Under low-speed, steady-state conditions, a smaller basic opening degree matches the reduced gas delivery volume of the compressor, preventing excessive refrigerant supply from reducing energy efficiency and thus fully utilizing the energy-saving potential of the wide-speed variable frequency compressor under low loads.

[0031] The controller can also determine a first opening constraint value and a second opening constraint value. The first opening constraint value represents the maximum value between a first minimum opening determined based on the refrigerant pressure on the suction side of the variable frequency compressor and a second minimum opening determined based on the refrigerant subcooling at the inlet of the flow control valve. The second opening constraint value represents the maximum opening determined based on the refrigerant subcooling at the inlet of the flow control valve. This maximum opening is used to limit the upper limit of the valve opening; the lower the refrigerant subcooling, the higher the flashover risk, and the smaller this maximum opening value, to prevent further increase in the liquid circuit pressure drop, which could lead to two-phase flow upstream of the valve.

[0032] Specifically, the first minimum opening degree is used to prevent insufficient liquid supply to the evaporator and triggering of low-pressure protection; the lower the suction pressure, the larger this opening degree value. The second minimum opening degree is used to prevent the valve opening from being too small, which would lead to excessive pressure drop in the liquid circuit and exacerbate the risk of flashover before the valve. By taking the maximum value of the two, the first opening degree constraint value simultaneously takes into account both suction side pressure safety and the stability of the refrigerant state before the valve.

[0033] In this embodiment, if the first opening constraint value is greater than the second opening constraint value, the controller controls the flow regulating valve to adjust the refrigerant flow based on the safe opening value. It is then determined that a conflict exists between the low-pressure protection requirement (requiring the opening value to be no lower than the higher lower limit) and the flashover prevention requirement (requiring the opening value to be no higher than the lower upper limit), and the flow regulating valve alone cannot simultaneously meet the safety requirements of the refrigeration system. In this case, the controller controls the flow regulating valve to adjust the refrigerant flow based on the safe opening value.

[0034] It should be noted that when the first opening constraint value (i.e., the first minimum opening determined based on the refrigerant pressure on the suction side) is greater than the second opening constraint value (i.e., the maximum opening determined based on the refrigerant subcooling at the inlet of the flow control valve), the refrigeration system is determined to have entered a safety boundary conflict state. In this situation, low-pressure protection requires the valve opening to be no lower than the higher first opening constraint value, while flashover prevention requires the valve opening to be no higher than the lower second opening constraint value. These two requirements cannot be met simultaneously, resulting in a conflict. The flow control valve alone cannot simultaneously meet the safety requirements of the refrigeration system.

[0035] At this point, the controller can maintain the flow regulating valve at a preset safe opening. This safe opening can be understood as a temporary opening value output by the controller to the flow regulating valve to maintain the safe operation of the refrigeration system when a conflict arises between the first minimum opening and the maximum opening. By controlling the flow regulating valve to maintain the preset safe opening when the first opening constraint value is greater than the second opening constraint value, the controller ensures the safe and stable operation of the refrigeration system in the event of abnormal operating conditions. This prevents the inverter compressor from shutting down due to low-pressure protection triggering, or prevents flashover of the refrigerant before the valve due to insufficient subcooling, which could lead to uncontrolled flow regulation.

[0036] For example, the safe opening degree can be a pre-set fixed opening degree value. This fixed opening degree value is an empirical value obtained by repeatedly testing on a prototype under operating conditions that are prone to triggering conflicts, such as high speed, high load, or high ambient temperature. Furthermore, the calibration process of the fixed opening degree value can cover multiple operating modes and speed combinations to ensure that it will not lead to the triggering of low-pressure protection or the aggravation of valve flashover in conflict scenarios.

[0037] For example, the safe opening degree can also be the target opening degree output in the most recent control cycle before the first opening degree constraint value exceeds the second opening degree constraint value. The controller can write the calculated target opening degree into a temporary storage area in each control cycle. When a conflict condition is detected, it directly reads the target opening degree output in the most recent control cycle from this temporary storage area as the safe opening degree. This method minimizes the valve opening change amplitude of the flow control valve at the moment of conflict, avoiding pressure fluctuations in the refrigeration system caused by sudden valve opening changes.

[0038] For example, the safe opening degree can also be the average of the first opening degree constraint value and the second opening degree constraint value. Specifically, the first minimum opening degree and the maximum opening degree can be arithmetically averaged to obtain an average value between the two. This average value can be regarded as a balance between low-pressure demand and flashover prevention, so that the valve opening degree is both higher than the maximum opening degree by a certain margin and lower than the first minimum opening degree by a certain range, leaving a buffer space for the recovery adjustment of both constraints.

[0039] By providing multiple alternative safe opening determination methods, the controller can flexibly select according to the actual product configuration, storage resources and control accuracy requirements. When the first opening constraint value is greater than the second opening constraint value, a safe opening is provided for the flow regulating valve. There is no need to force the wide-frequency inverter compressor to reduce the frequency due to safety concerns. This avoids the refrigeration system from shutting down directly or the refrigerant flow from going out of control due to conflicts. This fully releases the refrigeration potential of the wide-speed inverter compressor, while avoiding flow runaway caused by valve flash, and significantly improves the operational stability of the refrigeration system.

[0040] By determining the basic opening degree of the flow regulating valve based on the operating speed and refrigeration operation mode of the variable frequency compressor, feedforward matching of refrigerant flow rate with compressor gas delivery is achieved. By constructing a first minimum opening degree based on the suction-side refrigerant pressure and a second minimum opening degree based on the refrigerant subcooling before the valve, and taking the maximum value of these two as the first opening degree constraint value, and constructing a maximum opening degree based on the refrigerant subcooling before the valve as the second opening degree constraint value, dual dynamic definition of the low-pressure safety boundary and flashover safety boundary of the refrigeration system is achieved.

[0041] Furthermore, when the first opening constraint value is greater than the second opening constraint value, the refrigeration system is determined to enter a conflict state between low-pressure demand and flashover prevention. To address this, this solution controls the flow regulating valve to adjust the refrigerant flow based on a preset safe opening value. This safe opening value can be a pre-calibrated fixed value, the most recent effective opening value before the conflict, or the average of the constraint values. The aim is to maintain the basic operation of the refrigeration system during the conflict and avoid the inverter compressor from shutting down.

[0042] Through the aforementioned conflict arbitration mechanism, this disclosure is particularly effective in resolving the contradiction between low-pressure protection and flashover prevention under extreme operating conditions (such as high-temperature environments and ultra-high-speed temperature pulling), thereby freeing the variable frequency compressor from the constraints of high-speed operation and fully releasing the potential of the wide-speed variable frequency compressor in terms of refrigeration performance. At the same time, by maintaining the safe opening degree, it buys time for subsequent coordinated adjustments (such as condenser fan speed increase), ensuring the stable operation of the wide-speed variable frequency compressor across the entire speed range.

[0043] In some embodiments, the controller is also configured to perform, such as Figure 3 The flowchart of the refrigerator control method shown is as follows: S301. Determine the basic opening degree of the flow regulating valve based on the operating speed of the variable frequency compressor and the refrigeration operation mode of the refrigerator.

[0044] S302. Determine the first opening constraint value and the second opening constraint value.

[0045] S303. If the first opening constraint value is less than or equal to the second opening constraint value, then the opening to be adjusted is restricted between the first opening constraint value and the second opening constraint value to obtain the target opening. S304, The flow control valve adjusts the refrigerant flow based on the target opening degree.

[0046] It should be noted that steps S301 and S302 have been described in detail above and will not be repeated below. Steps S303 to S304 will be described in detail below.

[0047] In step S303, the opening to be adjusted is the base opening, or the corrected opening obtained by adding a correction amount to the base opening.

[0048] In step S303, the correction amount may include a return gas state correction amount (generated based on the difference between ambient temperature and return gas temperature) or a steady-state energy-saving correction amount (generated based on the compressor operating rate or the integral of the compartment temperature deviation). By introducing the correction amount, closed-loop fine-tuning can be achieved on the basis of feedforward control, further improving control accuracy and energy efficiency.

[0049] When the opening to be adjusted is the base opening (or the corrected opening), the controller executes the following limiting logic to determine the target opening: If the base opening is less than the first opening constraint value, it means that the current opening requirement is lower than the safety lower limit of the refrigeration system. In this case, the first opening constraint value will be used as the target opening to prevent insufficient liquid supply to the evaporator or triggering low-pressure protection. If the base opening is greater than the second opening constraint value, it means that the current opening requirement exceeds the upper limit of flash risk prevention and control. In this case, the second opening constraint value will be used as the target opening to avoid refrigerant vaporization before the valve leading to flow runaway. If the basic opening is between the first opening constraint value and the second opening constraint value, it means that the current opening requirement is within the safe and feasible region. In this case, the basic opening is taken as the target opening to achieve precise matching of flow rate and rotation speed.

[0050] Understandably, the first and second opening constraint values ​​dynamically define safety boundaries from the perspectives of low-pressure protection and flashover prevention, respectively. When the first opening constraint value is less than or equal to the second opening constraint value, it indicates that the lower limit of low-pressure demand is lower than the upper limit of flashover prevention, and there is no safety boundary conflict in the refrigeration system. The target opening can be freely output within this safety boundary. This allows the refrigerator to adaptively match the refrigerant flow rate and compressor gas delivery capacity over a wide speed range without manual adjustment.

[0051] In one implementation, the controller can also apply a slope limit to the base opening (i.e., limit the maximum change in opening within a single control cycle), and then compare the processed opening value with the first and second opening constraint values. This approach avoids pressure surges in the refrigeration system caused by sudden valve opening changes, further improving the system's operational stability. After determining the target opening, the controller outputs a corresponding drive control signal, such as a pulse width modulation signal or an analog voltage signal, to the flow control valve to regulate the refrigerant flow through it.

[0052] By determining the basic opening degree of the flow regulating valve based on the operating speed of the variable frequency compressor and the refrigeration operation mode of the refrigerator, and introducing a first opening degree constraint value and a second opening degree constraint value as dual constraints, the opening degree to be adjusted (the basic opening degree or its correction) is constrained within the feasible range between the two under non-conflict conditions. The flow regulating valve is controlled to adjust the refrigerant flow based on the target opening degree. This can simultaneously take into account the flow feedforward matching, closed-loop fine adjustment, low-pressure protection prevention, and flash risk control over a wide speed range. This allows the refrigerant flow to be dynamically matched with the gas delivery capacity of the variable frequency compressor over a wide speed range, thereby significantly improving the stability, reliability, and energy efficiency of the refrigerator refrigeration system.

[0053] In one embodiment, the refrigerator may further include an ambient temperature sensor and a return air temperature sensor. The ambient temperature sensor may be located on the outside of the refrigerator body or at the air inlet of a compartment, and is configured to collect the ambient temperature of the environment in which the refrigerator is located. As before... Figure 1 As shown, a return gas temperature sensor (not shown) can be installed on the return gas pipe 300 of the variable frequency compressor and configured to collect the return gas temperature of the variable frequency compressor. The ambient temperature sensor and the return gas temperature sensor can be electrically connected to the controller respectively, and transmit the collected temperature signals to the controller.

[0054] In one embodiment, the correction amount is a return gas state correction amount, such as... Figure 4 As shown, the controller is configured to obtain the opening to be adjusted in the following manner: S401: Receives the ambient temperature measured by the ambient temperature sensor and the return gas temperature of the variable frequency compressor measured by the return gas temperature sensor. S402. Generate a return gas status correction amount based on the difference between the ambient temperature and the return gas temperature. S403. The basic opening degree and the return air state correction amount are superimposed to obtain the opening degree to be adjusted.

[0055] In this embodiment, the return gas state correction amount is an opening adjustment amount generated based on the difference between the ambient temperature and the return gas temperature of the variable frequency compressor, used to increase or decrease the basic opening. The return gas state correction amount is used to reflect the refrigerant superheat state on the return gas side of the compressor, and to perform closed-loop fine adjustment of the feedforward basic opening so that the valve opening of the flow regulating valve can respond to the change in return gas temperature.

[0056] Specifically, the opening to be adjusted is the intermediate value of the opening after adding the base opening and the return gas state correction. The target opening is the final opening value output to the flow control valve after limiting the opening to be adjusted between the first opening constraint value and the second opening constraint value. By performing the above operations sequentially, the controller can add the return gas state correction to the base opening determined by the speed feedforward for feedback correction to obtain the opening to be adjusted, and then constrain the opening to be adjusted within the safe range formed by the first minimum opening and the maximum opening to obtain the target opening.

[0057] For example, the controller can receive the ambient temperature measured by an ambient temperature sensor and the return gas temperature of the variable frequency compressor measured by a return gas temperature sensor. The controller can calculate the difference between the ambient temperature and the return gas temperature of the variable frequency compressor. For example, generating a return gas status correction amount based on the difference can include several cases: In one implementation, when the difference exceeds a first preset temperature difference threshold, it indicates that the return gas temperature is abnormally low, potentially indicating over-supply of liquid or abnormal return gas. The controller can then generate a negative correction to reduce the base opening. The first preset temperature difference threshold can be calibrated through prototype testing, for example, it can be set to 3 Kelvin.

[0058] In another implementation, when the temperature difference is less than a second preset temperature difference threshold and the refrigerant pressure on the suction side is lower than a preset pressure reference value, it indicates insufficient liquid supply or excessive compressor suction overheating. The controller can then generate a positive correction to increase the base opening. The second preset temperature difference threshold can be a value close to 0 Kelvin.

[0059] In another implementation, when the difference is within a preset temperature difference range between the first preset temperature difference threshold and the second preset temperature difference threshold, for example, when the difference is between 0 Kelvin and 2 Kelvin, the controller can generate a zero correction amount, that is, it does not adjust the basic opening by increasing or decreasing.

[0060] It should be noted that the specific value of the return gas state correction amount can also be determined by comprehensively referring to tables or calculations based on the operating speed of the variable frequency compressor, the refrigeration operation mode, and the refrigerant pressure on the suction side.

[0061] For example, the opening degree to be adjusted can be obtained by superimposing the base opening degree with the return gas state correction amount. By generating the return gas state correction amount based on the difference between the ambient temperature and the return gas temperature of the inverter compressor, and superimposing the base opening degree with the return gas state correction amount to obtain the opening degree to be adjusted, a closed-loop feedback regulation of the return gas superheat state can be introduced on the basis of the base opening degree to complete the return gas state feedback correction of the base opening degree, achieve fine adjustment, realize accurate adaptive matching of refrigerant flow over a wide speed range, and improve the energy efficiency and stability of the refrigerator refrigeration system.

[0062] As one implementation method, the correction amount is the steady-state energy-saving correction amount, such as... Figure 5 As shown, the controller is configured to obtain the opening to be adjusted in the following manner: S501. When the refrigerator is in steady-state operation, generate steady-state energy-saving correction amount based on the compressor start-up rate or the integral of the compartment temperature deviation.

[0063] Among them, the steady-state operation state indicates that the difference between the refrigerator's compartment temperature and the set temperature is within the preset fluctuation range, and the change in the operating speed of the inverter compressor within the preset time is less than the preset speed threshold.

[0064] S502. The basic opening degree is superimposed with the steady-state energy-saving correction amount to obtain the opening degree to be adjusted.

[0065] Among them, the rate of change of steady-state energy saving correction is lower than the rate of change of return gas state correction, and the absolute value of steady-state energy saving correction is limited to no more than the preset correction range.

[0066] Understandably, when the refrigerator is in steady-state operation, a steady-state energy-saving correction is generated based on the compressor operating rate or the integral of the compartment temperature deviation. The base opening degree is then superimposed with the steady-state energy-saving correction degree to obtain the opening degree to be adjusted.

[0067] In this embodiment, the steady-state energy-saving correction is an opening adjustment amount generated during the steady-state operation phase based on the compressor operating rate or the integral of the compartment temperature deviation. It is used to slowly fine-tune the basic opening degree, specifically to optimize valve opening for energy saving by utilizing long-cycle operating trends, while avoiding interference with the transient response of the refrigeration system. In other words, a slow integral correction to the basic opening degree is introduced after the refrigeration system enters the steady-state phase to improve energy efficiency.

[0068] For example, the controller can continuously monitor the difference between the compartment temperature and the set temperature. If the difference is within a preset fluctuation range, such as ±0.5 Kelvin, and monitors the change in the operating speed of the inverter compressor within a preset time, if the change is less than a preset speed threshold, such as less than 50 revolutions per minute, then the refrigerator can be determined to have entered a steady-state operating state. For example, generating the steady-state energy-saving correction amount can include various methods.

[0069] In one implementation, the controller can look up the steady-state energy-saving correction amount in a table based on the compressor operating rate. The operating rate can be understood as the proportion of time the compressor is in the on state within a control cycle. The higher the operating rate, the greater the cooling demand. The corresponding steady-state energy-saving correction amount can be a positive value to appropriately increase the valve opening.

[0070] In another implementation, the controller can integrate the compartment temperature deviation, which represents the difference between the actual temperature of the compartment and the set temperature. The integral result is multiplied by a preset integral coefficient to obtain the steady-state energy-saving correction. The integral coefficient can be a small value to ensure that the correction changes slowly.

[0071] It should be noted that the rate of change of the steady-state energy-saving correction can be lower than the rate of change of the return gas state correction. The return gas state correction can be generated based on the difference between the ambient temperature and the return gas temperature of the variable frequency compressor, and is used to quickly adjust the base opening for each control cycle. The steady-state energy-saving correction, on the other hand, can be updated over a longer adjustment period, such as every few minutes. The absolute value of the steady-state energy-saving correction can be limited to no more than a preset correction margin, which can be a small opening value, such as 3%, to prevent the steady-state correction from being too large and affecting system stability. The base opening and the steady-state energy-saving correction are then superimposed to obtain the opening to be adjusted.

[0072] By introducing a steady-state energy-saving correction based on the compressor operating rate or the integral of the compartment temperature deviation, the basic opening degree can be slowly and finely adjusted when the refrigerator is in steady-state operation. This allows for long-term energy-saving optimization without interfering with the system's transient response, thereby improving the refrigerator's energy efficiency under low-speed steady-state conditions.

[0073] In one embodiment, the refrigeration operation mode may include a single refrigerator mode, a single freezer mode, and a dual-circuit refrigerator / freezer operation mode. A single refrigerator mode represents the refrigerator operating with only the refrigerator solenoid valve activated and the freezer solenoid valve closed; in this mode, the cooling demand primarily comes from the refrigerator compartment. A single freezer mode represents the refrigerator operating with only the freezer solenoid valve activated and the refrigerator solenoid valve closed; in this mode, the cooling demand primarily comes from the freezer compartment. A dual-circuit refrigerator / freezer operation mode represents the refrigerator operating with both the refrigerator and freezer solenoid valves activated simultaneously; in this mode, both the refrigerator and freezer compartments have cooling demand, and the refrigeration system load is at its maximum.

[0074] In this embodiment, the controller can pre-store a speed-to-opening mapping table, which includes sub-tables corresponding to single refrigeration mode, single freezing mode, and dual-path refrigeration / freezing operation mode, respectively. These sub-tables record the correspondence between the variable frequency compressor's operating speed and the basic opening of the flow regulating valve. Different refrigeration operation modes can correspond to independent mapping sub-tables to reflect the matching relationship between refrigerant flow demand and compressor speed under different loads.

[0075] In some embodiments, during the operation of the flow control valve based on a safe opening degree, the operating state of the condenser fan and / or the variable frequency compressor is adjusted such that the first opening degree constraint value is less than or equal to the second opening degree constraint value.

[0076] During the operation of the flow control valve based on the safe opening degree, the controller adjusts the operating state of the condenser fan and / or the variable frequency compressor. The purpose is to change the refrigerant pressure on the suction side and the refrigerant subcooling at the inlet of the flow control valve in a conflict state where the first opening degree constraint value is greater than the second opening degree constraint value, so that the first opening degree constraint value falls back to less than or equal to the second opening degree constraint value, thereby restoring from the current conflict state to the non-conflict state, i.e., the normal control state.

[0077] As one implementation method, the controller adjusts the operating status of the condenser fan, specifically configured as follows: Based on the difference between the refrigerant subcooling at the inlet of the flow regulating valve and the preset subcooling threshold, the speed increment of the condenser fan is determined, and the condenser fan is controlled to increase its speed according to the speed increment, starting from the base speed. If the refrigerant subcooling at the inlet of the flow regulating valve is greater than the preset subcooling threshold, and the refrigerant pressure on the suction side is greater than the sum of the low-pressure warning threshold and the hysteresis value, the condenser fan is controlled to return to the base speed.

[0078] In this embodiment, the refrigerant subcooling at the inlet of the flow control valve reflects the degree of subcooling of the liquid refrigerant upstream of the valve. The higher the subcooling, the lower the risk of flashover when the refrigerant flows through the flow control valve. A preset subcooling threshold is used to characterize the critical value of subcooling when the refrigerant upstream of the valve is in a safe liquid phase state. This threshold can be the aforementioned first subcooling threshold, and the specific value can be calibrated during the prototype testing phase based on the physical properties of the refrigerant and the system piping parameters.

[0079] The speed increment of the condenser fan is positively correlated with the subcooling difference; that is, the greater the deviation of the subcooling from the threshold, the larger the speed increment. The base speed is the normal operating speed of the condenser fan in the current cooling operation mode (such as the default speed determined by looking up a table based on the ambient temperature).

[0080] By increasing the speed from the base speed, the condenser's heat dissipation capacity can be enhanced, increasing the refrigerant subcooling out of the condenser, thereby increasing the second opening constraint value (maximum opening) and creating conditions for resolving conflicts. When the refrigerant subcooling at the inlet of the flow control valve recovers and the suction pressure returns to a safe range (greater than the sum of the low-pressure warning threshold and the hysteresis value), the condenser fan is controlled to return to the base speed to avoid unnecessary energy consumption.

[0081] As another implementation method, or in combination with the above-mentioned condenser fan adjustment method, the controller adjusts the operating status of the variable frequency compressor, specifically configured as follows: If the refrigerant pressure on the suction side remains less than or equal to the sum of the low-pressure warning threshold and the hysteresis value within a set time, or if the refrigerant subcooling at the inlet of the flow regulating valve remains less than or equal to the preset subcooling threshold, an abnormal status signal is output to the inverter controller of the inverter compressor, so that the inverter controller performs frequency limiting operation or protection operation; when the refrigerant pressure on the suction side exceeds the sum of the low-pressure warning threshold and the hysteresis value, and the refrigerant subcooling at the inlet of the flow regulating valve exceeds the preset subcooling threshold and continues for a preset recovery time, the output of the abnormal status signal stops.

[0082] In this embodiment, the set time is the anomaly determination duration (e.g., 30 to 120 seconds) starting from the trigger of conflict arbitration, used to determine whether the coordinated adjustment is effective. The low-pressure warning threshold is the sum of the low-pressure protection trigger pressure and the preset warning margin, used to provide a safety buffer boundary. The preset recovery time (e.g., 10 to 30 seconds) is used to prevent misjudgments caused by short-term parameter fluctuations.

[0083] If the refrigeration system fails to recover within a set time, an abnormal status signal is output. In response to this signal, the inverter controller can perform either frequency limiting (limiting the maximum speed) or protection (reducing the speed to a safe range), thereby reducing the compressor's suction demand, causing the suction pressure to rise, and lowering the first opening constraint value (first minimum opening). When the suction pressure and the refrigerant subcooling at the inlet of the flow regulating valve simultaneously meet the conditions and continue for the preset recovery time, the abnormal status signal is stopped, the inverter controller releases the restriction, and the refrigeration system resumes normal operation.

[0084] Through the aforementioned coordinated adjustment mechanism, this disclosed example addresses both the "supply side" (increasing the speed of the condenser fan to enhance subcooling) and the "demand side" (limiting the compressor frequency to reduce suction demand) simultaneously, effectively resolving the safety boundary conflict between low-pressure protection and flashover prevention. The setting of the low-pressure warning threshold and hysteresis value avoids frequent oscillations in the control logic, ensuring the smoothness and reliability of the refrigeration system's recovery to normal operation.

[0085] As one implementation, the controller has a preset first subcooling threshold and a second subcooling threshold, with the first subcooling threshold being greater than the second subcooling threshold; the controller is specifically configured to determine the second opening constraint value in the following manner: If the refrigerant subcooling is greater than or equal to the first subcooling threshold, the preset maximum opening degree will be used as the second opening degree constraint value. If the refrigerant subcooling is less than the first subcooling threshold and greater than or equal to the second subcooling threshold, then the maximum opening degree determined by the refrigerant subcooling, the operating speed of the variable frequency compressor, and the refrigeration operation mode shall be used as the second opening degree constraint value. If the refrigerant subcooling is less than the second subcooling threshold, the maximum opening value determined by the refrigerant subcooling, the operating speed of the variable frequency compressor, and the refrigeration operation mode will be used as the second opening constraint value, and the condenser fan speed will be increased to increase the refrigerant subcooling.

[0086] In one embodiment, the controller has a preset first subcooling threshold and a second subcooling threshold, wherein the first subcooling threshold is greater than the second subcooling threshold. The first subcooling threshold corresponds to a safety threshold, used to determine whether the refrigerant before the valve is in a safe state without flashover risk; the second subcooling threshold corresponds to a risk threshold, used to determine whether the refrigerant before the valve has entered a high flashover risk state. The controller determines the second opening constraint value (i.e., the maximum opening determined based on the subcooling of the refrigerant before the valve) in the following manner to achieve graded and progressive flashover prevention: Scenario 1: No risk of flashing.

[0087] If the refrigerant subcooling is greater than or equal to the first subcooling threshold, it indicates that the refrigerant before the valve is in a safe state without the risk of flashover. At this time, the controller will use the preset maximum opening (e.g., 100% opening) as the second opening constraint value. In this state, the maximum opening is not limited, and the flow control valve can operate normally based on the basic opening or the modified opening, while still being limited by the lower limit of the first opening constraint value.

[0088] The second scenario: a state of mild flash risk.

[0089] If the refrigerant subcooling is less than the first subcooling threshold but greater than or equal to the second subcooling threshold, it indicates that the refrigerant upstream of the valve is in a state of slight flashover risk. The controller queries a pre-stored mapping relationship based on the refrigerant subcooling, the operating speed of the variable frequency compressor, and the refrigeration operation mode to determine the corresponding maximum valve opening, and uses this maximum opening as the second opening constraint value. The maximum opening monotonically decreases as the subcooling decreases to limit the upper limit of the valve opening and prevent an increase in liquid pressure drop that could lead to two-phase flow upstream of the valve.

[0090] The third scenario: a high-flash risk state.

[0091] If the refrigerant subcooling is less than the second subcooling threshold, it indicates that the refrigerant before the valve is in a high-flash-risk state. The controller also determines the corresponding maximum opening degree based on the refrigerant subcooling, the operating speed of the variable frequency compressor, and the refrigeration operation mode, using this as the second opening degree constraint value, and further controls the condenser fan to increase its speed. Specifically, the controller can determine the condenser fan speed increment based on the difference between the refrigerant subcooling and the second subcooling threshold, increasing the condenser fan speed according to this increment to enhance condenser heat dissipation, increase refrigerant subcooling, and promote system recovery to a safe state. If the refrigerant subcooling is less than the second subcooling threshold and continues for more than a preset timeout period, the controller can also output an abnormal status signal to the variable frequency controller of the variable frequency compressor to execute more stringent frequency limiting or protection operations.

[0092] By performing a three-level comparison of refrigerant subcooling based on a first subcooling threshold and a second subcooling threshold, and dynamically determining the second opening constraint value and collaborative adjustment strategy under different risk levels, this disclosure enables differentiated intervention for flashover risks. This not only ensures the freedom of flow regulation over a wide operating speed at low risks, but also ensures the safety of the refrigeration system and improves the stability and reliability of the refrigerator refrigeration system over a wide operating speed range by limiting the maximum opening and increasing the condenser fan speed at high risks.

[0093] In some embodiments, the controller has a preset low-pressure warning threshold, which is the sum of the low-pressure protection trigger pressure and the preset warning margin. The low-pressure protection trigger pressure represents the critical suction pressure value in the refrigeration system that triggers the low-pressure protection mechanism to stop the compressor or reduce its frequency; the preset warning margin represents the early intervention pressure difference before entering the low-pressure protection phase, which is used to generate an opening constraint before the actual suction pressure reaches the low-pressure protection trigger pressure, thereby achieving early intervention.

[0094] The controller is specifically configured to determine the first minimum opening degree as follows: if the refrigerant pressure on the suction side is less than the low-pressure warning threshold, the first minimum opening degree is determined based on the difference between the suction side refrigerant pressure and the low-pressure warning threshold. Specifically, the lower the suction side refrigerant pressure, the larger the first minimum opening degree. That is, the lower limit of the valve opening is dynamically determined by the deviation between the suction pressure and the warning threshold. A larger deviation indicates a higher low-pressure risk, and the corresponding lower opening limit is also higher. This requires the flow control valve opening to not be lower than this lower limit to ensure evaporator liquid supply and avoid false triggering of the low-pressure protection.

[0095] For example, there are several ways to determine the first minimum opening: In one implementation, the controller can pre-store a mapping table between the difference and the first minimum opening degree. When the refrigerant pressure on the suction side is detected to be lower than the low-pressure warning threshold, the controller calculates the difference between the two and queries the mapping table based on this difference to directly obtain the corresponding first minimum opening degree.

[0096] In another implementation, the first minimum opening degree can be obtained by linearly calculating the difference according to a preset proportional coefficient. For example, the difference can be multiplied by a positive calibration coefficient and then added to the system's preset basic minimum opening degree to obtain the first minimum opening degree. This ensures that the lower the refrigerant pressure on the suction side (i.e., the larger the difference), the larger the calculated first minimum opening degree.

[0097] In another implementation, the first minimum opening degree can be determined by combining the operating speed of the inverter compressor and the refrigeration operation mode of the refrigerator. For example, the correspondence between the difference in operating speed and refrigeration operation mode and the first minimum opening degree can be pre-calibrated. When querying or calculating, parameters that match the current operating speed and refrigeration operation mode can be called to obtain a first minimum opening degree that better fits the current system state.

[0098] In some embodiments, the controller is specifically configured to determine the second minimum opening degree by determining the second minimum opening degree and the maximum opening degree based on the refrigerant subcooling degree at the inlet of the flow regulating valve, the operating speed of the variable frequency compressor, and the refrigeration operation mode.

[0099] For example, the system can query a pre-stored flashover prevention mapping table based on the refrigerant subcooling at the inlet of the flow regulating valve, the current operating speed of the variable frequency compressor, and the current refrigeration operation mode to determine the second minimum opening degree and the corresponding maximum opening degree. The maximum opening degree is greater than the second minimum opening degree, and both tend to decrease as the refrigerant subcooling degree decreases, while adapting to increases in operating speed.

[0100] The second minimum opening is used to prevent excessive pressure drop in the liquid circuit due to insufficient valve opening, which would exacerbate the risk of flashover before the valve. Its value can be appropriately increased as the refrigerant subcooling decreases, so as to force the maintenance of a basic flow rate when there is a high risk of flashover and prevent the refrigeration system from entering a dead loop.

[0101] By presetting a low-pressure warning threshold and dynamically generating a first minimum opening that increases with decreasing pressure based on the pressure difference when the refrigerant pressure on the suction side is lower than the low-pressure warning threshold, and simultaneously determining a corresponding second minimum opening when the subcooling before the valve is insufficient, this disclosure can construct lower limits based on low-pressure safety and flashover prevention, respectively. The first opening constraint value is the maximum of the two, thereby increasing the lower limit of the flow control valve opening in advance before the refrigeration system approaches low-pressure protection, while also taking into account the risk of flashover before the valve, effectively avoiding insufficient evaporator liquid supply and false triggering of low-pressure protection, and ensuring the reliability and stability of the refrigeration system over a wide operating range.

[0102] In one embodiment, the refrigerator may further include a condenser outlet pressure sensor and a condenser outlet temperature sensor. The condenser outlet pressure sensor may be located at the refrigerant outlet line of the condenser and configured to collect the refrigerant pressure at the condenser outlet. The condenser outlet temperature sensor may be located at the refrigerant outlet line of the condenser and configured to collect the refrigerant temperature at the condenser outlet. The condenser outlet pressure sensor and the condenser outlet temperature sensor may be electrically connected to the controller, respectively, and transmit the collected pressure and temperature signals to the controller.

[0103] In this embodiment, as Figure 6 As shown, the controller is specifically configured to determine the refrigerant subcooling in the following manner: S601. Calculate the condenser outlet subcooling based on the condenser outlet pressure measured by the condenser outlet pressure sensor and the condenser outlet temperature measured by the condenser outlet temperature sensor.

[0104] In this embodiment, the controller can receive the condenser outlet pressure Pc measured by the condenser outlet pressure sensor, query the pre-stored refrigerant thermodynamic property table, and obtain the condensing saturation temperature Tsat corresponding to Pc; simultaneously, it can receive the condenser outlet temperature Tc measured by the condenser outlet temperature sensor, and calculate the difference between the condensing saturation temperature Tsat and the condenser outlet temperature Tc to obtain the condenser outlet subcooling SCout, i.e., SCout = Tsat. Tc. The subcooling at the condenser outlet reflects the initial liquid state of the refrigerant when it flows out of the condenser.

[0105] S602. Determine the subcooling loss based on the liquid pressure drop, local resistance, and heat absorption temperature rise between the condenser outlet and the flow regulating valve inlet.

[0106] In this embodiment, the subcooling loss is the amount of subcooling reduction caused by pressure drop along the liquid path, local resistance (such as the resistance of pipe fittings such as dryer filters and solenoid valves) and temperature rise due to heat absorption in the pipeline during the process of refrigerant flowing from the condenser outlet to the flow regulating valve inlet.

[0107] In some embodiments, the controller pre-stores a subcooling loss mapping table covering a wide speed range and all cooling operation modes. This mapping table can be calibrated during prototype testing by measuring the temperature difference and pressure difference between the condenser outlet and the flow control valve inlet under different compressor speeds, flow control valve openings, cooling operation modes, and condenser fan speeds. The controller, based on the current operating speed, flow control valve opening, cooling operation mode, and condenser fan speed, calls the corresponding subcooling loss mapping table to retrieve the subcooling loss ΔSCloss under the current operating condition. For example, under high ambient temperature conditions, the temperature rise of the pipeline increases, and the ΔSCloss retrieved by the controller increases accordingly to match the actual subcooling attenuation under the actual operating conditions and avoid subcooling calculation errors.

[0108] S603. Subtract the subcooling loss from the subcooling at the condenser outlet to obtain the refrigerant subcooling at the inlet of the flow regulating valve.

[0109] In this embodiment, the controller subtracts the subcooling loss ΔSCloss from the condenser outlet subcooling SCout to obtain the refrigerant subcooling SCin at the inlet of the flow regulating valve, i.e., SCin = SCout. ΔSCloss. This SCin is used to reflect the true subcooling state of the refrigerant at the inlet of the flow control valve.

[0110] In an alternative implementation, pressure and temperature sensors can be directly installed at the inlet of the flow regulating valve. The controller collects the valve inlet pressure Pv and valve inlet temperature Tv, queries the saturation temperature Tvsat corresponding to Pv, and directly calculates the effective subcooling SCin = Tvsat before the valve. TV. This method offers higher measurement accuracy and is suitable for high-end models with stricter requirements for flashover control. Both methods of obtaining subcooling can be flexibly selected based on product positioning, and both are within the scope of protection of this disclosure.

[0111] By using the above method to determine the subcooling before the valve, there is no need to add additional pressure and temperature sensors before the valve, which can effectively reduce hardware costs. Based on the real-time operating parameters, the subcooling loss can be dynamically corrected, which can ensure the accuracy of the subcooling calculation and provide a reliable input basis for flash prevention and safety boundary conflict arbitration, further improving the operational stability of the refrigeration system under wide speed conditions.

[0112] As one implementation method, the refrigeration operation modes include single refrigeration mode, single freezing mode, and dual-path refrigeration and freezing operation mode; the speed and opening degree mapping table includes sub-tables corresponding to the single refrigeration mode, single freezing mode, and dual-path refrigeration and freezing operation mode, respectively.

[0113] Still Figure 1As shown, the refrigerator body 100 may also be equipped with a condenser 201, a dryer filter 202, a refrigeration capillary tube 203a, a freezing capillary tube 203b, a refrigeration evaporator 204a, and a freezing evaporator 204b. The refrigeration and freezing branches can be connected in parallel, and each branch can be equipped with a refrigeration solenoid valve 205a and a freezing solenoid valve 205b. The controller can switch between single refrigeration mode, single freezing mode, or dual refrigeration and freezing operation mode by controlling the on / off state of the solenoid valves.

[0114] In some embodiments, such as Figure 7 As shown, the controller, based on the operating speed of the inverter compressor and the refrigeration mode of the refrigerator, queries a pre-stored speed-to-opening mapping table to determine the basic opening of the flow regulating valve, which is specifically configured as follows: S701. Based on the operating speed and cooling operation mode, call the corresponding speed and opening degree mapping sub-table; S702. If the operating speed is consistent with any speed point in the speed and opening degree mapping sub-table, then the opening degree value corresponding to the speed point shall be used as the basic opening degree. S703. If the operating speed is between two adjacent speed points in the speed and opening mapping sub-table, then the opening value corresponding to the two adjacent speed points is linearly interpolated to obtain the basic opening.

[0115] For example, the controller can call the corresponding speed and opening degree mapping sub-table according to the currently identified cooling operation mode. For instance, when the refrigerator is in single refrigeration mode, the controller can call the mapping sub-table corresponding to single refrigeration mode. This sub-table can store multiple speed points and their corresponding basic opening degree values ​​within a wide speed range. For example, the basic opening degree is 32% when the operating speed is 800 rpm, and 68% when the operating speed is 4,800 rpm.

[0116] When the operating speed matches any speed point in the mapping sub-table, the controller can directly use the opening value corresponding to that speed point as the base opening. For example, if the current operating speed is 4,800 revolutions per minute, the controller can directly use 68% as the base opening.

[0117] If the operating speed falls between two adjacent speed points in the mapping sub-table, the controller can linearly interpolate the opening values ​​corresponding to the two adjacent speed points to obtain the base opening. For example, if the current operating speed is 2,000 rpm, falling between 1,600 rpm and 2,400 rpm, the base opening corresponding to 1,600 rpm is 38%, and the base opening corresponding to 2,400 rpm is 45%. The controller can calculate the base opening corresponding to 2,000 rpm as approximately 41.5% based on the speed ratio.

[0118] In another implementation, if the operating speed exceeds the maximum speed point of the mapping sub-table, the controller can use the opening value corresponding to the maximum speed point as the basic opening; if the operating speed is lower than the minimum speed point of the mapping sub-table, the controller can use the opening value corresponding to the minimum speed point as the basic opening to prevent table lookup from exceeding the limit.

[0119] By pre-storing corresponding speed and opening degree mapping sub-tables for single refrigeration mode, single freezing mode, and dual refrigeration and freezing operation mode, and calling the corresponding sub-tables according to the operating speed and refrigeration operation mode when determining the basic opening degree, the value is directly taken when the speed point matches the record in the table, and the basic opening degree is obtained by linear interpolation when the speed point is between adjacent speed points. This allows the basic opening degree of the flow control valve to change continuously and smoothly with the compressor speed in different refrigeration operation modes, achieving feedforward fast matching over a wide speed range.

[0120] In one embodiment, the refrigerator may further include a refrigerator solenoid valve and a freezer solenoid valve. The refrigerator solenoid valve may be connected in series in the refrigerator branch, located downstream of the dryer filter and before the inlet of the refrigerator capillary tube, and is configured to control the flow of refrigerant in the refrigerator branch in response to on / off commands from the controller. The freezer solenoid valve may be connected in series in the freezer branch, located downstream of the dryer filter and before the inlet of the freezer capillary tube, and is configured to control the flow of refrigerant in the freezer branch in response to on / off commands from the controller. The refrigerator and freezer solenoid valves may be electrically connected to the controller respectively, receiving level signals or relay drive signals output by the controller. The controller is further configured to: In response to the mode switching command, the basic opening degree corresponding to the target mode to be switched is determined. The mode switching command is used to indicate that the refrigeration operation mode is switched from the current mode to the target mode. The current mode and the target mode are different and are one of the following: single refrigeration mode, single freezing mode, or dual refrigeration and freezing operation mode. The flow control valve is adjusted from its current opening to the base opening corresponding to the target mode to be switched to, according to a preset rate of change. When the difference between the actual opening of the flow regulating valve and the basic opening corresponding to the target mode is less than the preset error range, the refrigeration solenoid valve and / or the freezing solenoid valve are controlled to switch the refrigeration operation mode from the current mode to the target mode; and after the switch is completed, the operation of controlling the flow regulating valve to adjust the refrigerant flow based on the target opening is resumed according to the basic opening, the first opening constraint value and the second opening constraint value.

[0121] For example, a mode switching command can be understood as a signal triggered by the refrigerator's control system or user operation, indicating that the cooling operation mode should be switched from the current mode to the target mode. The current mode can represent the cooling mode that the refrigerator is currently running in before the switch, and the target mode can represent the cooling mode that the refrigerator will run in after the switch. The current mode and the target mode are different and can be one of the following: single refrigerator mode, single freezer mode, or dual refrigerator and freezer operation mode.

[0122] For example, in response to a mode switching command, the controller can determine the base opening degree corresponding to the target mode to be switched to. For instance, the controller can call a speed-to-opening degree mapping sub-table corresponding to the target mode based on the current operating speed of the variable frequency compressor and the target mode to be switched to. If the operating speed matches a speed point in the mapping sub-table, the opening degree value corresponding to that speed point can be used as the base opening degree corresponding to the target mode; if the operating speed is between two adjacent speed points, linear interpolation can be performed on the opening degree values ​​corresponding to the two adjacent speed points to obtain the base opening degree corresponding to the target mode. After obtaining the base opening degree corresponding to the target mode, the controller can control the flow regulating valve to gradually adjust from the current opening degree to the base opening degree corresponding to the target mode according to a preset rate of change.

[0123] Understandably, the preset rate of change is a parameter that limits the maximum change in the opening of the flow control valve within each control cycle, used to achieve a smooth transition of the valve opening. The preset rate of change can be obtained through prototype testing and calibration; for example, it can be set to adjust the opening change by 1% to 3% per control cycle, or to adjust the opening change by 1% to 5% every 100 milliseconds.

[0124] During the adjustment process, the controller can acquire the actual opening degree of the flow regulating valve in real time and calculate the difference between the actual opening degree and the base opening degree corresponding to the target mode. When this difference is less than the preset error range (i.e., to determine whether the actual opening degree of the flow regulating valve has reached the allowable deviation range of the base opening degree corresponding to the target mode), for example, less than one to two percent of the opening degree difference, the controller can control the operation of the refrigeration solenoid valve and / or the freezing solenoid valve.

[0125] Specifically, when switching from a single refrigeration mode to a dual-circuit refrigeration / freezing mode, the controller can, after the valve adjustment is complete, control the refrigeration solenoid valve to switch from the closed to the open state. Similarly, when switching from a dual-circuit refrigeration / freezing mode to a single freezing mode, the controller can, after the valve adjustment is complete, control the refrigeration solenoid valve to switch from the open to the closed state. Conversely, when switching from a single freezing mode to a single refrigeration mode, the controller can, after the valve adjustment is complete, control the freezing solenoid valve to close and the refrigeration solenoid valve to open. After the solenoid valves complete their operation, the controller can resume controlling the flow regulating valve to adjust the refrigerant flow based on the target opening degree, according to the base opening degree, the first opening degree constraint value, and the second opening degree constraint value; that is, it re-enters the normal operation state or the conflict arbitration control cycle.

[0126] By first determining the base opening degree corresponding to the target mode, the flow regulating valve is gradually adjusted to the base opening degree corresponding to the target mode according to a preset rate of change. The on / off state of the solenoid valve is only switched when the difference between the actual opening degree and the base opening degree corresponding to the target mode is less than the preset error range. This can avoid the pressure shock of the refrigeration system caused by sudden changes in the opening degree of the flow regulating valve and the simultaneous on / off of the branch during the switching of refrigeration operation modes, and ensure a smooth transition of refrigerant flow. After the switching is completed, the operation of controlling the flow regulating valve to adjust the refrigerant flow based on the target opening degree is resumed, so that the refrigeration system can quickly enter the target mode, that is, the stable control state of the new mode.

[0127] As one implementation method, the controller executes the control flow regulating valve to adjust the refrigerant flow based on the target opening degree. Specifically, it is configured to: calculate the difference between the target opening degree of the current control cycle and the opening degree output in the previous control cycle to obtain the opening degree change; if the opening degree change degree is greater than the preset maximum change step size, then control the flow regulating valve to adjust the refrigerant flow based on the target opening degree according to the preset maximum change step size.

[0128] In one embodiment, the target opening degree of the current control cycle can be obtained as described above, that is, by limiting the opening degree to be adjusted between a first opening degree constraint value and a second opening degree constraint value to obtain the final opening degree value output to the flow control valve. The opening degree output in the previous control cycle is the opening degree value corresponding to the drive signal actually sent to the flow control valve by the controller in the control cycle immediately preceding the current control cycle.

[0129] The change in valve opening can be understood as the difference between the target opening in the current control cycle and the opening output in the previous control cycle. This difference reflects the magnitude of the change in the valve opening command over two consecutive control cycles. The preset maximum change step size can be understood as the maximum allowable change in the flow control valve opening within each control cycle. Specifically, it is used to limit the valve's execution rate and prevent drastic jumps in the opening command within a single control cycle.

[0130] In one implementation, if the target opening degree is greater than the sum of the opening degree output in the previous control cycle and the preset maximum change step size, then the opening degree output in the previous control cycle plus the preset maximum change step size is used as the actual output opening degree; if the target opening degree is less than the opening degree output in the previous control cycle minus the preset maximum change step size, then the opening degree output in the previous control cycle minus the preset maximum change step size is used as the actual output opening degree, and the flow regulating valve is controlled to adjust the refrigerant flow rate based on the actual output opening degree.

[0131] In another implementation, the preset maximum change step size can be dynamically adjusted according to the operating speed of the variable frequency compressor. For example, the higher the operating speed, the more the preset maximum change step size can be increased to meet the system's need for rapid flow response at high speeds. Alternatively, during the switching of refrigeration operation modes, the preset maximum change step size can be a larger value than that used during steady-state operation to speed up the flow regulation during the mode switching process.

[0132] In another implementation, the preset maximum change step size can be calibrated during the prototype testing phase. For example, it can be set to allow a change of 1% to 5% in the opening degree per control cycle, and the control cycle can be 100 milliseconds to 1 second, thereby ensuring that the mechanical action of the flow regulating valve is smooth and the pressure fluctuation of the refrigeration system is controllable.

[0133] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this disclosure.

[0134] Corresponding to the above implementation example Figure 2 The refrigerator control method shown is as follows: Figure 8 This is a schematic diagram of a refrigerator control device provided in an embodiment of the present disclosure. The device can be implemented as part or all of a computer device by software, hardware, or a combination of both. This computer device can be... Figure 9 The electronic device shown.

[0135] Reference Figure 8 The refrigerator control device 800 includes: The first determining unit 801 is used to determine the basic opening degree of the flow regulating valve based on the operating speed of the variable frequency compressor and the refrigeration operation mode of the refrigerator. The second determining unit 802 is used to determine a first opening constraint value and a second opening constraint value, wherein the first opening constraint value represents the maximum value between a first minimum opening determined by the refrigerant pressure on the suction side of the variable frequency compressor and a second minimum opening determined based on the refrigerant subcooling at the inlet of the flow regulating valve, and the second opening constraint value represents the maximum opening determined based on the refrigerant subcooling at the inlet of the flow regulating valve. The control unit 803 is used to control the flow regulating valve to adjust the refrigerant flow based on a safe opening degree if the first opening degree constraint value is greater than the second opening degree constraint value; wherein the safe opening degree is a pre-calibrated fixed opening degree value, which is determined by prototype testing; or, the safe opening degree is the target opening degree output in the most recent control cycle before the first opening degree constraint value is greater than the second opening degree constraint value; or, the safe opening degree is the average value of the first opening degree constraint value and the second opening degree constraint value.

[0136] It should be noted that the refrigerator control device provided in the above embodiments is only an example of the division of the above functional modules. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0137] The functional units and modules in the above embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of the embodiments of this disclosure.

[0138] It should be noted that the information interaction and execution process between the above-mentioned devices / units are based on the same concept as the method embodiments of this disclosure. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0139] This disclosure also provides an electronic device, which includes one or more processors and a memory; The memory is coupled to one or more processors. The memory is used to store computer program code, which includes computer instructions. One or more processors invoke the computer instructions to cause the electronic device to perform the refrigerator control method described above.

[0140] Figure 9This is a schematic diagram of the structure of an electronic device provided in an embodiment of this disclosure. The electronic device 900 can be a mobile phone, smart screen, tablet computer, wearable electronic device, in-vehicle electronic device, augmented reality (AR) device, virtual reality (VR) device, laptop computer, ultra-mobile personal computer (UMPC), netbook, personal digital assistant (PDA), projector, or a communication device such as a server, storage device, or base station, or a smart car, etc. This disclosure does not limit the specific type of electronic device.

[0141] The memory 901 can be used to store computer programs 902 and modules. The processor 903 executes various functional applications and data processing of the electronic device by running the software programs and modules stored in the memory 901. The memory 901 may mainly include a program storage area and a data storage area. The program storage area may store the operating system, application programs required for at least one function (such as sound playback function, image playback function, etc.), etc.; the data storage area may store data created according to the use of the electronic device (such as audio data, telephone directory, etc.). In addition, the memory 901 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0142] The processor 903 may include one or more processors such as a central processing unit (CPU), an application processor (AP), and a baseband processor. The processor can serve as the nerve center and command center of the electronic device. The processor 903 can generate operation control signals based on instruction opcodes and timing signals to control instruction fetching and execution. The memory 901 can be used to store executable program code, including instructions. The processor 903 executes various functional applications and data processing of the electronic device by running the instructions stored in the memory. The memory 901 may include a program storage area and a data storage area, such as storing data for audio signals to be played. For example, the memory may be Double Data Rate Synchronous Dynamic Random Access Memory (DDR) or Flash memory.

[0143] This disclosure also provides a computer-readable storage medium storing computer instructions; when the computer-readable storage medium is used on an electronic device, it causes the electronic device to execute the aforementioned refrigerator control method.

[0144] The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or can include one or more data storage devices such as servers or data centers that can be integrated with media. The available medium can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media, or semiconductor media (e.g., solid-state disks (SSDs)).

[0145] This disclosure also provides a computer program product containing computer instructions, which, when run on an electronic device, enables the electronic device to execute the aforementioned refrigerator control method.

[0146] The computer storage medium and computer program product provided in the above-described embodiments are used to execute the methods provided above. Therefore, the beneficial effects they can achieve can be referred to the beneficial effects corresponding to the methods provided above, and will not be repeated here.

[0147] In the above embodiments, implementation can also be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this disclosure are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer, or a data storage device such as a server or data center that integrates one or more available media. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk drive (HDD), or solid-state drive (SSD), etc., and the storage medium can also include combinations of the above types of memory.

[0148] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0149] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments claimed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this disclosure.

[0150] In the embodiments provided in this disclosure, it should be understood that the disclosed devices / electronic devices and methods can be implemented in other ways. For example, the device / electronic device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings or direct couplings or communication connections may be through some interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0151] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0152] The technical features of the various embodiments described above in this disclosure can be combined arbitrarily without conflict. For the sake of brevity, this specification does not describe all possible combinations, but as long as these combinations do not violate the technical spirit of this disclosure, they should all be considered within the scope of this disclosure. Based on the content disclosed in this disclosure, those skilled in the art can reasonably combine, delete, or replace the technical features of the above embodiments according to actual needs, and such modifications and variations all fall within the protection scope of this disclosure.

[0153] The above-described embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit it. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this disclosure, and should all be included within the protection scope of this disclosure.

Claims

1. A refrigerator, characterized in that, The system includes a housing, and a variable frequency compressor, a flow regulating valve, a condenser fan, and a controller disposed within the housing. The controller is electrically connected to the variable frequency compressor, the flow regulating valve, and the condenser fan, respectively. The controller is configured to: Based on the operating speed of the variable frequency compressor and the refrigeration operation mode of the refrigerator, the basic opening of the flow regulating valve is determined by querying the pre-stored speed-to-opening mapping table. A first opening constraint value and a second opening constraint value are determined, wherein the first opening constraint value represents the maximum value between a first minimum opening determined by the refrigerant pressure on the suction side of the variable frequency compressor and a second minimum opening determined based on the refrigerant subcooling at the inlet of the flow regulating valve, and the second opening constraint value represents the maximum opening determined based on the refrigerant subcooling at the inlet of the flow regulating valve. If the first opening constraint value is greater than the second opening constraint value, the flow regulating valve is controlled to adjust the refrigerant flow based on a safe opening value; wherein, the safe opening value is a pre-calibrated fixed opening value, which is determined through prototype testing; or, the safe opening value is the target opening value output in the most recent control cycle before the first opening constraint value is greater than the second opening constraint value; or, the safe opening value is the average of the first opening constraint value and the second opening constraint value. If the first opening constraint value is less than or equal to the second opening constraint value, the opening to be adjusted is restricted between the first opening constraint value and the second opening constraint value to obtain the target opening, and the flow regulating valve is controlled to adjust the refrigerant flow based on the target opening. Wherein, the opening to be adjusted is the base opening, or the corrected opening obtained by superimposing a correction amount on the base opening; when the opening to be adjusted is the base opening, the target opening is determined in the following manner: if the base opening is less than the first opening constraint value, then the first opening constraint value is used as the target opening; if the base opening is greater than the second opening constraint value, then the second opening constraint value is used as the target opening; if the base opening is between the first opening constraint value and the second opening constraint value, then the base opening is used as the target opening.

2. The refrigerator according to claim 1, characterized in that, The refrigerator also includes an ambient temperature sensor and a return gas temperature sensor, which are electrically connected to the controller. The correction amount is a return gas state correction amount, and the controller is configured to obtain the opening degree to be adjusted in the following manner: Receive the ambient temperature measured by the ambient temperature sensor and the return gas temperature of the variable frequency compressor measured by the return gas temperature sensor; A return gas state correction amount is generated based on the difference between the ambient temperature and the return gas temperature. The base opening degree is superimposed with the return gas state correction amount to obtain the opening degree to be adjusted.

3. The refrigerator according to claim 1, characterized in that, The correction amount is a steady-state energy-saving correction amount, and the controller is configured to obtain the opening degree to be adjusted in the following manner: When the refrigerator is in a steady-state operation state, a steady-state energy-saving correction amount is generated based on the compressor start-up rate or the integral of the compartment temperature deviation. The steady-state operation state indicates that the difference between the compartment temperature and the set temperature of the refrigerator is within a preset fluctuation range, and the change in the operating speed of the variable frequency compressor within a preset time is less than a preset speed threshold. The basic opening degree is superimposed with the steady-state energy-saving correction amount to obtain the opening degree to be adjusted.

4. The refrigerator according to claim 1, characterized in that, The controller is also configured to: During the operation of the flow regulating valve based on the safe opening degree, the operating state of the condenser fan and / or the variable frequency compressor is adjusted so that the first opening degree constraint value is less than or equal to the second opening degree constraint value.

5. The refrigerator according to claim 4, characterized in that, The controller is configured to adjust the operating status of the condenser fan and / or the variable frequency compressor, specifically as follows: Based on the difference between the refrigerant subcooling at the inlet of the flow regulating valve and a preset subcooling threshold, the speed increment of the condenser fan is determined, and the condenser fan is controlled to increase its speed according to the speed increment, starting from the base speed; if the refrigerant subcooling at the inlet of the flow regulating valve is greater than the preset subcooling threshold, and the refrigerant pressure on the suction side is greater than the sum of the low-pressure warning threshold and the hysteresis value, then the condenser fan is controlled to return to the base speed; and / or, If the refrigerant pressure on the suction side remains less than or equal to the sum of the low-pressure warning threshold and the hysteresis value within a set time, or if the refrigerant subcooling at the inlet of the flow regulating valve remains less than or equal to the preset subcooling threshold, an abnormal status signal is output to the inverter controller of the inverter compressor, so that the inverter controller performs frequency limiting operation or protection operation; when the refrigerant pressure on the suction side exceeds the sum of the low-pressure warning threshold and the hysteresis value, and the refrigerant subcooling at the inlet of the flow regulating valve exceeds the preset subcooling threshold and continues for a preset recovery time, the output of the abnormal status signal stops. Wherein, the low-pressure warning threshold is the sum of the low-pressure protection trigger pressure and the preset warning margin, and the preset supercooling threshold is the preset risk trigger supercooling value.

6. The refrigerator according to claim 1, characterized in that, The controller has a preset first subcooling threshold and a second subcooling threshold, wherein the first subcooling threshold is greater than the second subcooling threshold; the controller is specifically configured to determine the second opening constraint value in the following manner: If the refrigerant subcooling degree is greater than or equal to the first subcooling degree threshold, then the preset maximum opening degree is used as the second opening degree constraint value; If the refrigerant subcooling is less than the first subcooling threshold and greater than or equal to the second subcooling threshold, then the maximum opening degree determined by the refrigerant subcooling, the operating speed of the variable frequency compressor, and the refrigeration operation mode shall be used as the second opening degree constraint value. If the refrigerant subcooling is less than the second subcooling threshold, the maximum opening value determined by the refrigerant subcooling, the operating speed of the variable frequency compressor, and the refrigeration operation mode will be used as the second opening constraint value, and the condenser fan will be controlled to increase its speed to increase the refrigerant subcooling.

7. The refrigerator according to claim 6, characterized in that, The controller has a preset low-pressure warning threshold, which is the sum of the low-pressure protection trigger pressure and the preset warning margin. The controller is specifically configured to determine the first minimum opening degree in the following manner: if the refrigerant pressure on the suction side is less than the low pressure warning threshold, the first minimum opening degree is determined based on the difference between the refrigerant pressure on the suction side and the low pressure warning threshold, wherein the lower the refrigerant pressure on the suction side, the larger the first minimum opening degree. The controller is specifically configured to determine the second minimum opening degree by: determining the second minimum opening degree and the maximum opening degree based on the refrigerant subcooling degree, the operating speed of the variable frequency compressor and the refrigeration operation mode, wherein the maximum opening degree is greater than the second minimum opening degree.

8. The refrigerator according to any one of claims 1 to 7, characterized in that, The refrigerator also includes a condenser outlet pressure sensor and a condenser outlet temperature sensor, which are electrically connected to the controller. The controller is specifically configured to determine the refrigerant subcooling in the following manner: The condenser outlet subcooling is calculated based on the condenser outlet pressure measured by the condenser outlet pressure sensor and the condenser outlet temperature measured by the condenser outlet temperature sensor. The subcooling loss is determined based on the liquid pressure drop, local resistance, and heat absorption temperature rise between the condenser outlet and the inlet of the flow regulating valve. The refrigerant subcooling at the inlet of the flow regulating valve is obtained by subtracting the subcooling loss from the subcooling at the condenser outlet.

9. The refrigerator according to any one of claims 1 to 7, characterized in that, The refrigeration operation modes include single refrigeration mode, single freezing mode, and dual-path refrigeration and freezing operation mode; the speed and opening degree mapping table includes sub-tables of speed and opening degree mapping corresponding to the single refrigeration mode, the single freezing mode, and the dual-path refrigeration and freezing operation mode, respectively; The controller, based on the operating speed of the variable frequency compressor and the refrigeration mode of the refrigerator, queries a pre-stored speed-to-opening mapping table to determine the basic opening of the flow regulating valve, specifically configured as follows: Based on the operating speed and the cooling operation mode, call the corresponding speed and opening degree mapping sub-table; If the operating speed is consistent with any speed point in the speed and opening mapping sub-table, then the opening value corresponding to the speed point is taken as the basic opening. If the operating speed is between two adjacent speed points in the speed-opening mapping sub-table, then the opening value corresponding to the two adjacent speed points is linearly interpolated to obtain the basic opening.

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