Method for determining the charge of a refrigerant for a refrigerator refrigeration system and controller

Abstract

The application provides a refrigerant filling quantity determination method and a controller for a refrigerator refrigerating system, and belongs to the technical field of refrigerator refrigerant filling. The method comprises the following steps: adjusting the opening degree of a first electronic expansion valve to the maximum, and controlling the compressor to continuously and uninterruptedly refrigerate; collecting the refrigeration chamber temperature and the freezing chamber temperature of the refrigerator, determining the refrigeration chamber temperature and the freezing chamber temperature when the refrigeration chamber temperature and the freezing chamber temperature are stable, recording the refrigeration chamber temperature and the freezing chamber temperature, and collecting the inlet temperature and the outlet temperature of a first evaporator; determining the optimal opening degree of the first electronic expansion valve according to the recorded refrigeration chamber temperature and freezing chamber temperature; controlling the opening degree of the first electronic expansion valve to remain at the optimal opening degree; and determining the optimal filling quantity of the refrigerant according to the temperature difference between the outlet temperature and the inlet temperature of the first evaporator. The method can make the refrigerator refrigerating system have the optimal refrigerant filling quantity.

Description

Technical Field

[0001] This invention relates to the field of refrigerator refrigerant charging technology, and in particular to a method and controller for determining the refrigerant charging amount for a refrigerator refrigeration system. Background Technology

[0002] Against the backdrop of energy conservation and emission reduction, how to further reduce the power consumption of refrigerators has always been a challenge for the industry. Capillary tubes play a role in throttling and pressure reduction in refrigerator refrigeration systems, preparing for subsequent evaporation. However, capillary tubes cannot actively regulate refrigerant flow; the refrigerant flow mainly changes with the compressor speed, and is also affected by ambient temperature and the refrigerator's heat load.

[0003] Existing electronic expansion valves for refrigerators have a certain throttling effect, but most of them are limited to program logic control and analysis. They do not truly replace capillary tubes and can only supplement the throttling effect. They cannot truly replace capillary tubes and reduce power consumption. They lack practical applications and there is no corresponding method for adjusting the refrigerant charge to achieve the optimal charge level. Summary of the Invention

[0004] One objective of the first aspect of the present invention is to provide a method for determining the refrigerant charge amount of a refrigerator refrigeration system that performs throttling and heat exchange through a first electronic expansion valve and a heat exchange tube, so that the refrigerator refrigeration system can have an optimal refrigerant charge amount.

[0005] A second aspect of the present invention aims to provide a method for determining the charge amount of a refrigerator refrigeration system equipped with a refrigeration evaporator and a freezing evaporator, which can ensure that the charge amount is the minimum required to maintain the refrigeration effect, avoid resource waste, and help save costs.

[0006] A third aspect of the present invention is to provide a controller for performing the above-described method for determining the infusion volume.

[0007] Specifically, the present invention provides a method for determining the refrigerant charge amount for a refrigerator refrigeration system. The refrigerator refrigeration system includes a compressor, a condenser, a heat exchange tube, a first electronic expansion valve, a first evaporator, and a return gas pipe, which are connected in series and form a loop. The first evaporator is disposed in the freezer compartment. The heat exchange tube is in contact with the return gas pipe to exchange heat with it. The refrigerator refrigeration system controls the refrigerant flow rate through the first electronic expansion valve. The method includes:

[0008] Adjust the opening of the first electronic expansion valve to the maximum to control the compressor to continuously refrigerate without stopping;

[0009] Collect the refrigerator compartment temperature and freezer compartment temperature. Based on the refrigerator compartment temperature and freezer compartment temperature, determine when the refrigerator compartment temperature and freezer compartment temperature are stable and record the refrigerator compartment temperature and freezer compartment temperature. Collect the inlet temperature and outlet temperature of the first evaporator.

[0010] The optimal opening degree of the first electronic expansion valve is determined based on the recorded refrigerator compartment temperature and the freezer compartment temperature;

[0011] The opening degree of the first electronic expansion valve is controlled to be maintained at the optimal opening degree;

[0012] The optimal refrigerant charge is determined based on the temperature difference between the outlet and inlet temperatures of the first evaporator.

[0013] Optionally, the step of determining the optimal opening degree of the first electronic expansion valve based on the recorded refrigerator compartment temperature and the freezer compartment temperature includes:

[0014] The opening degree of the first electronic expansion valve is controlled to decrease by a preset opening value, and the changes in the temperature of the refrigerator compartment and the temperature of the freezer compartment are monitored.

[0015] Determine whether the temperature of the refrigerator compartment and the temperature of the freezer compartment are no longer decreasing; if so, determine that the current opening of the first electronic expansion valve is the optimal opening.

[0016] Otherwise, continue to reduce the opening of the first electronic expansion valve until the temperature of the refrigerator compartment and the temperature of the freezer compartment no longer decrease, and take the opening of the first electronic expansion valve corresponding to the point when the temperature of the refrigerator compartment and the temperature of the freezer compartment no longer decreases as the optimal opening.

[0017] Optionally, the step of further reducing the opening of the first electronic expansion valve includes:

[0018] Continue to control the opening of the first electronic expansion valve to decrease by a preset value.

[0019] Optionally, the step of determining the optimal refrigerant charge based on the temperature difference between the outlet and inlet temperatures of the first evaporator includes:

[0020] Monitor the outlet and inlet temperatures of the first evaporator;

[0021] Determine whether the temperature difference between the outlet temperature and the inlet temperature of the first evaporator is greater than or equal to a preset value. If so, take the current refrigerant charge as the optimal charge.

[0022] Otherwise, the refrigerant charge will be reduced by a preset amount until the temperature difference between the outlet and inlet temperatures of the first evaporator is less than the preset value, and the refrigerant charge when the temperature difference between the outlet and inlet temperatures of the first evaporator is less than the preset value will be taken as the optimal charge amount.

[0023] Optionally, the step of controlling the opening of the first electronic expansion valve to decrease by a preset opening value includes:

[0024] The regulating motor controlling the first electronic expansion valve decreases by a preset number of steps.

[0025] Specifically, the present invention also provides a method for determining the refrigerant charge amount for a refrigerator refrigeration system. The refrigerator refrigeration system includes a compressor, a condenser, a heat exchange tube, a first electronic expansion valve, a first evaporator, and a return gas pipe connected in series and forming a loop. The first evaporator is located in the freezer compartment. The heat exchange tube contacts the return gas pipe to exchange heat with it. The refrigerator refrigeration system controls the refrigerant flow rate through the first electronic expansion valve. The refrigerator refrigeration system further includes a refrigeration branch connected in parallel to both ends of the freezer branch. The refrigeration branch includes a second evaporator and a second electronic expansion valve connected in series. The second evaporator is a refrigeration evaporator located in the refrigeration compartment. The freezer branch includes the first evaporator and the first electronic expansion valve connected in series. The method includes:

[0026] Adjust the opening of the first electronic expansion valve and the second electronic expansion valve to the maximum to control the compressor to continuously refrigerate without stopping;

[0027] Collect the refrigerator compartment temperature and freezer compartment temperature. Based on the refrigerator compartment temperature and freezer compartment temperature, determine when the refrigerator compartment temperature and freezer compartment temperature are stable and record the refrigerator compartment temperature and freezer compartment temperature. Collect the inlet temperature and outlet temperature of the first evaporator.

[0028] The first optimal opening degree of the first electronic expansion valve is determined based on the recorded freezer temperature;

[0029] The second optimal opening degree of the second electronic expansion valve is determined based on the recorded refrigerator compartment temperature;

[0030] The opening degree of the first electronic expansion valve is controlled to be maintained at the first optimal opening degree, and the opening degree of the second electronic expansion valve is maintained at the second optimal opening degree;

[0031] The optimal refrigerant charge is determined based on the temperature difference between the outlet and inlet temperatures of the first evaporator.

[0032] Optionally, the step of determining the first optimal opening degree of the first electronic expansion valve based on the recorded freezer compartment temperature includes:

[0033] The opening degree of the first electronic expansion valve is controlled to decrease by a first preset opening value, and the change in the temperature of the freezer compartment is monitored;

[0034] Determine whether the temperature of the freezer compartment is no longer decreasing; if so, determine that the current opening of the first electronic expansion valve is the first optimal opening.

[0035] Otherwise, continue to reduce the opening of the first electronic expansion valve until the freezer temperature no longer decreases, and take the opening of the first electronic expansion valve corresponding to the point when the freezer temperature no longer decreases as the first optimal opening.

[0036] Optionally, the step of determining the second optimal opening degree of the second electronic expansion valve based on the recorded refrigerator compartment temperature includes:

[0037] The opening degree of the second electronic expansion valve is controlled to decrease to a second preset opening value, and the change in the temperature of the refrigerator compartment is monitored.

[0038] Determine whether the temperature of the refrigerator compartment is no longer decreasing; if so, determine that the current opening of the second electronic expansion valve is the second optimal opening.

[0039] Otherwise, continue to reduce the opening of the second electronic expansion valve until the temperature of the refrigerator compartment no longer decreases, and set the opening of the second electronic expansion valve corresponding to the point when the temperature of the refrigerator compartment no longer decreases as the second optimal opening.

[0040] Optionally, the step of determining the optimal refrigerant charge based on the temperature difference between the outlet and inlet temperatures of the first evaporator includes:

[0041] Monitor the outlet and inlet temperatures of the first evaporator;

[0042] Determine whether the temperature difference between the outlet temperature and the inlet temperature of the first evaporator is greater than or equal to a preset value. If so, take the current refrigerant charge as the optimal charge.

[0043] Otherwise, the refrigerant charge will be reduced by a preset amount until the temperature difference between the outlet and inlet temperatures of the first evaporator is less than the preset value, and the refrigerant charge when the temperature difference between the outlet and inlet temperatures of the first evaporator is less than the preset value will be taken as the optimal charge amount.

[0044] In particular, the present invention also provides a controller, including a memory and a processor, wherein the memory stores a control program, which, when executed by the processor, is used to implement the refrigerant charge determination method described in any of the preceding claims.

[0045] According to one embodiment of the present invention, the optimal opening degree of the first electronic expansion valve can be determined by monitoring the temperature of the refrigerator compartment and the temperature of the freezer compartment. Then, the first electronic expansion valve is kept at the optimal opening degree, and the optimal refrigerant charge is determined by the inlet temperature and outlet temperature of the first evaporator. This provides a method for determining the refrigerant charge of a refrigerator refrigeration system that performs throttling and heat exchange through the first electronic expansion valve and the heat exchange tube respectively, so that the refrigerator refrigeration system can have the optimal refrigerant charge.

[0046] According to one embodiment of the present invention, by gradually reducing the opening of the first electronic expansion valve and monitoring the refrigerator compartment temperature and the freezer compartment temperature, when further reducing the opening of the first electronic expansion valve will not cause the refrigerator compartment temperature and the freezer compartment temperature to decrease, the current opening of the first electronic expansion valve is taken as the optimal opening, that is, the minimum opening that can maintain the refrigeration effect is obtained.

[0047] According to one embodiment of the present invention, by gradually reducing the refrigerant charge and observing the temperature difference between the inlet and outlet of the first evaporator, when further reducing the refrigerant charge would cause the temperature difference between the inlet and outlet of the first evaporator to be greater than or equal to a preset value, the current refrigerant charge is taken as the optimal charge, which can obtain the most economical refrigerant charge, that is, the minimum charge that guarantees the cooling effect.

[0048] According to one embodiment of the present invention, a method for determining the refrigerant charge of a refrigerator refrigeration system equipped with a refrigeration evaporator and a freezing evaporator is also provided. After adjusting the first optimal opening degree of the first electronic expansion valve and the second optimal opening degree of the second electronic expansion valve respectively, the optimal charge amount is adjusted according to the change of the inlet and outlet temperature difference of the first evaporator. When the refrigerant charge amount is taken as the optimal charge amount, it can be ensured that it is the minimum charge amount to maintain the refrigeration effect, without causing resource waste and helping to save costs.

[0049] The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0050] The following sections will describe some specific embodiments of the invention in detail by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

[0051] Figure 1 This is a schematic diagram of the structure of a refrigerator refrigeration system corresponding to a refrigerant charge determination method according to an embodiment of the present invention.

[0052] Figure 2 This is a flowchart of a method for determining the refrigerant charge amount according to an embodiment of the present invention;

[0053] Figure 3 This is a flowchart of the step of determining the optimal opening degree of the first electronic expansion valve in a refrigerant charge determination method according to an embodiment of the present invention;

[0054] Figure 4 This is a flowchart of the step of determining the optimal refrigerant charge in a refrigerant charge determination method according to an embodiment of the present invention;

[0055] Figure 5 This is a schematic diagram of the structure of a refrigerator refrigeration system corresponding to the refrigerant charge determination method according to another embodiment of the present invention;

[0056] Figure 6 This is a flowchart of a method for determining the refrigerant charge amount according to another embodiment of the present invention;

[0057] Figure 7 This is a schematic diagram of the controller according to an embodiment of the present invention. Detailed Implementation

[0058] In the description of this embodiment, it should be understood that the terms "inner" and "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0059] In the description of this embodiment, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0060] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature, that is, include one or more of that feature. When a feature "includes or contains" one or more of the features it encompasses, unless otherwise specifically stated, this indicates that other features are not excluded and may be further included.

[0061] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," and "coupling," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art should be able to understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0062] Furthermore, in the description of this embodiment, "above" or "below" the second feature can include direct contact between the first and second features, or it can include contact between the first and second features through another feature between them. That is, in the description of this embodiment, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "below" of the second feature can mean the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0063] Unless otherwise specified, all terms (including technical and scientific terms) used in the description of this embodiment have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0064] With the improvement of flow control accuracy and the advancement of structural design of electronic expansion valves, their refrigerant control is fast, precise, and has a wide adjustment range, resulting in outstanding energy saving and cooling effects. This led the inventors to conceive the idea of ​​using a high-precision electronic expansion valve to regulate the flow rate in the refrigerator's refrigeration circuit, thereby replacing the capillary tube. They discovered that, with the refrigerator's bubble layer and volume remaining constant, matching the electronic expansion valve's flow opening with the compressor's speed can further reduce power consumption.

[0065] Figure 1 This is a schematic diagram of the structure of a refrigerator refrigeration system 100 corresponding to a refrigerant charge determination method according to an embodiment of the present invention. Figure 2 This is a flowchart of a method for determining the refrigerant charge amount according to an embodiment of the present invention. Figure 1As shown, in one embodiment, the refrigerator refrigeration system 100 includes a compressor 10, a condenser 20, a heat exchange tube 30, a first electronic expansion valve 40, a first evaporator 50, and a return pipe 60, which are connected in series and form a loop. The first evaporator 50 is located in the freezer compartment of the refrigerator. The heat exchange tube 30 is in contact with the return pipe 60 to exchange heat with it. The refrigerator refrigeration system 100 controls the refrigerant flow rate through the first electronic expansion valve 40. That is to say, the refrigerator refrigeration system 100 in this embodiment eliminates the capillary tube and only uses the first electronic expansion valve 40 as a throttling element. In the prior art, the position where the capillary tube is set is replaced by the heat exchange tube 30. The heat exchange tube 30 can be a pipe with the same diameter as other ordinary pipes in the refrigeration circuit. The heat exchange tube 30 here only plays the role of heat exchange and does not play the role of throttling. The heat exchange tube 30 and the return pipe 60 are attached to each other. The heat exchange effect can be ensured by wrapping them with the same insulation layer. The heat exchange tube 30 can be a straight tube or wrapped around the return pipe 60 to increase the heat exchange area. Under normal circumstances, the heat exchange effect between the heat exchange tube 30 and the return pipe 60 can be ensured by wrapping them with the same insulation layer.

[0066] The refrigerator's refrigeration system 100 achieves throttling and heat exchange functions respectively through a first electronic expansion valve 40 and a heat exchange tube 30 connected in series, which is equivalent to separating the throttling and heat exchange functions of the capillary tube in the prior art. By attaching the heat exchange tube 30 to the return gas pipe 60, the heat exchange efficiency can be increased (generally better than that of the capillary tube), making the pre-cooling of the heat exchange tube 30 and the preheating of the return gas pipe 60 more complete, reducing the waste of cold energy, improving the actual coefficient of performance (COP) of the compressor 10, and reducing the refrigerator's power consumption.

[0067] Furthermore, the refrigerator refrigeration system 100 can be shut down by completely closing the first electronic expansion valve 40. Therefore, the system no longer needs to be equipped with a special electric valve to control the shutdown of the system, which helps to reduce the number of parts and save costs.

[0068] like Figure 2 As shown, the present invention provides a method for determining the refrigerant charge amount for a refrigerator refrigeration system. Before refrigerant is charged into the refrigerator, the optimal charge amount is determined in advance using this method. In one embodiment, the method includes:

[0069] In step S100, the opening of the first electronic expansion valve 40 is adjusted to the maximum, controlling the compressor 10 to continuously refrigerate without stopping. Of course, at this time, the refrigerator refrigeration system 100 piping has been filled with an initial amount of refrigerant, which can generally be determined based on the refrigerator's volume, the thickness and density of the insulation layer, and the heat transfer coefficient.

[0070] Step S200: Collect the refrigerator compartment temperature Tc and the freezer compartment temperature Td. Based on the refrigerator compartment temperature Tc and the freezer compartment temperature Td, determine when the refrigerator compartment temperature Tc and the freezer compartment temperature Td are stable, that is, when the refrigerator compartment temperature Tc and the freezer compartment temperature Td are almost unchanged. Record the refrigerator compartment temperature Tc and the freezer compartment temperature Td, and collect the inlet temperature Ti and the outlet temperature To of the first evaporator 50.

[0071] Step S300: Determine the optimal opening degree of the first electronic expansion valve 40 based on the recorded refrigerator compartment temperature Tc and freezer compartment temperature Td.

[0072] By continuously starting the compressor 10, when the refrigerator operating temperature and the temperature inside the refrigerator reach equilibrium, the optimal opening of the first electronic expansion valve 40 can be determined by changing the opening degree of the first electronic expansion valve 40 and then observing the changes in the refrigerator compartment temperature Tc and the freezer compartment temperature Td.

[0073] In step S400, the opening degree of the first electronic expansion valve 40 is controlled to be maintained at the optimal opening degree.

[0074] In step S500, the optimal refrigerant charge is determined based on the temperature difference between the outlet temperature To and the inlet temperature Ti of the first evaporator 50.

[0075] The temperature difference between the outlet temperature To and the inlet temperature Ti of the first evaporator 50 (i.e., the value of the outlet temperature To minus the inlet temperature Ti of the first evaporator 50) can reflect whether the refrigerant charge is sufficient. Therefore, the optimal refrigerant charge can be determined by the temperature difference between the outlet temperature To and the inlet temperature Ti of the first evaporator 50.

[0076] This embodiment determines the optimal opening degree of the first electronic expansion valve 40 by monitoring the refrigerator compartment temperature Tc and the freezer compartment temperature Td. Then, the first electronic expansion valve 40 is kept at the optimal opening degree, and the optimal refrigerant charge is determined by the inlet temperature Ti and outlet temperature To of the first evaporator 50. This provides a method for determining the refrigerant charge of a refrigerator refrigeration system 100 that performs throttling and heat exchange through the first electronic expansion valve 40 and the heat exchange tube 30, respectively, so that the refrigerator refrigeration system 100 can have the optimal refrigerant charge.

[0077] Figure 3 This is a flowchart illustrating the step of determining the optimal opening degree of the first electronic expansion valve 40 in a refrigerant charge determination method according to an embodiment of the present invention. Figure 3 As shown, in a further embodiment, step S300 includes:

[0078] Step S302: Control the opening of the first electronic expansion valve 40 to decrease the preset opening value, and monitor the changes in the refrigerator compartment temperature Tc and the freezer compartment temperature Td.

[0079] The adjustment mechanism of an electronic expansion valve is generally a stepper motor. Therefore, the opening degree of the electronic expansion valve is controlled by the number of steps of the stepper motor. The electronic expansion valves used in refrigerators typically have an adjustable step range of 100-300 steps. Correspondingly, the preset opening value can be a specific step value (unit adjustment steps), such as the opening degree corresponding to 20 steps. In one embodiment, the opening degree of the first electronic expansion valve 40 is controlled by decreasing the preset number of steps through the adjustment motor of the first electronic expansion valve 40. Of course, when the adjustable step range of the first electronic expansion valve 40 is larger, the unit adjustment steps can be increased proportionally. Therefore, in another embodiment, the unit adjustment steps can be set according to a value between 5% and 10% of the total steps. Ideally, this unit adjustment step number should be rounded down.

[0080] Step S304: Determine whether the refrigerator compartment temperature Tc and the freezer compartment temperature Td are no longer decreasing. If yes, proceed to step S306; otherwise, return to step S302 and continue to reduce the opening of the first electronic expansion valve 40 (the pre-opening value can still be reduced each time) until the refrigerator compartment temperature Tc and the freezer compartment temperature Td are no longer decreasing. The opening of the first electronic expansion valve 40 corresponding to the point when the refrigerator compartment temperature Tc and the freezer compartment temperature Td are no longer decreasing is taken as the optimal opening.

[0081] Step S306: Determine the current opening degree of the first electronic expansion valve 40 as the optimal opening degree.

[0082] The principle behind the above-mentioned optimal opening adjustment process is as follows: If the refrigerator compartment temperature Tc or the freezer compartment temperature Td decreases during the process of reducing the opening of the first electronic expansion valve 40, it indicates that the opening of the first electronic expansion valve 40 can be further reduced, and the current opening is uneconomical. Adjust the opening of the first electronic expansion valve 40 until the refrigerator compartment temperature Tc and the freezer compartment temperature Td no longer decrease after further reducing the opening of the first electronic expansion valve 40. This indicates that further reducing the opening of the first electronic expansion valve 40 will affect the cooling effect. At this point, the critical opening of the first electronic expansion valve 40 is found, which is the above-mentioned optimal opening.

[0083] In this embodiment, by gradually reducing the opening of the first electronic expansion valve 40 and monitoring the refrigerator compartment temperature Tc and the freezer compartment temperature Td, the current opening of the first electronic expansion valve 40 is taken as the optimal opening when further reducing the opening of the first electronic expansion valve 40 will not cause the refrigerator compartment temperature Tc and the freezer compartment temperature Td to decrease. This means that the minimum opening that can maintain the cooling effect is obtained.

[0084] Figure 4 This is a flowchart illustrating the step of determining the optimal refrigerant charge in a refrigerant charge determination method according to an embodiment of the present invention. In a further embodiment, as... Figure 4As shown, step S500 includes:

[0085] Step S502: Monitor the outlet temperature To and inlet temperature Ti of the first evaporator 50.

[0086] Step S504: Determine whether the temperature difference between the outlet temperature To and the inlet temperature Ti of the first evaporator 50 is greater than or equal to a preset value Ts. If yes, proceed to step S506; otherwise, proceed to step S508. The preset value Ts can be any value between 1 and 5℃, such as 1℃, 3℃, or 5℃.

[0087] Step S506: Take the current refrigerant charge as the optimal charge.

[0088] Step S508: Reduce the refrigerant charge amount by a preset amount and return to step S504 until the temperature difference between the outlet temperature To and the inlet temperature Ti of the first evaporator 50 is less than a preset value Ts. The refrigerant charge amount at which the temperature difference between the outlet temperature To and the inlet temperature Ti of the first evaporator 50 is less than the preset value Ts is taken as the optimal charge amount. The preset amount can be set according to the initial amount of refrigerant, for example, 3%-5% of the initial amount. Assuming the initial amount is 80g, the preset amount is 3g.

[0089] The principle behind the above-mentioned optimal refrigerant charge adjustment process is as follows: When the refrigerant charge is reduced, if the difference between the outlet temperature To and the inlet temperature Ti of the first evaporator 50 is less than the preset value Ts, meaning the temperature difference between the inlet and outlet To of the first evaporator 50 is not significant, it indicates that the refrigerant charge is sufficient, allowing the liquid refrigerant to undergo isothermal evaporation in the first evaporator 50, and the inlet and outlet temperatures To of the first evaporator 50 are almost identical. At this point, the refrigerant charge can be gradually reduced until the difference between the outlet temperature To and the inlet temperature Ti of the first evaporator 50 is greater than or equal to the preset value Ts. This indicates that there is insufficient refrigerant; after all the liquid refrigerant has evaporated, the temperature will rise, resulting in an increased temperature difference between the inlet and outlet of the evaporator. This process allows the optimal refrigerant charge to be determined.

[0090] In this embodiment, by gradually reducing the refrigerant charge and observing the temperature difference between the inlet and outlet of the first evaporator 50, when further reducing the refrigerant charge would cause the temperature difference between the inlet and outlet of the first evaporator 50 to be greater than or equal to the preset value Ts, the current refrigerant charge is taken as the optimal charge, which can obtain the most economical refrigerant charge, that is, the minimum charge to ensure the cooling effect.

[0091] Figure 5 This is a schematic diagram of the structure of a refrigerator refrigeration system 100 corresponding to a refrigerant charge determination method according to another embodiment of the present invention. Figure 5As shown, in another embodiment, the refrigerator refrigeration system 100 includes a compressor 10, a condenser 20, a heat exchange tube 30, a first electronic expansion valve 40, a first evaporator 50, and a return pipe 60, which are connected in series and form a loop. The first evaporator 50 is located in the freezer compartment of the refrigerator. The heat exchange tube 30 is in contact with the return pipe 60 to exchange heat with it. The refrigerator refrigeration system 100 controls the refrigerant flow rate through the first electronic expansion valve 40. The refrigerator refrigeration system 100 also includes a refrigeration branch connected in parallel to both ends of the freezer branch. The refrigeration branch includes a second evaporator 70 and a second electronic expansion valve 80 connected in series. The second evaporator 70 is a refrigeration evaporator located in the refrigeration compartment. The freezer branch includes the first evaporator 50 and the first electronic expansion valve 40 connected in series.

[0092] The refrigerator refrigeration system 100 includes a freezing evaporator and a refrigeration evaporator, which refrigerate the freezer compartment and the refrigerator compartment respectively. Both evaporators achieve throttling and heat exchange through a combination of electronic expansion valves and heat exchange tubes 30, which can also reduce the waste of cooling capacity, improve the actual performance coefficient of the compressor 10 and reduce the power consumption of the refrigerator.

[0093] Figure 6 This is a flowchart of a method for determining the refrigerant charge amount according to another embodiment of the present invention. The present invention also provides a method for determining the refrigerant charge amount for a refrigerator refrigeration system 100 in the above-described embodiment including a first evaporator 50 and a second evaporator 70, such as... Figure 6 As shown, in one embodiment, the method includes:

[0094] In step S10, the opening degree of the first electronic expansion valve 40 and the second electronic expansion valve 80 is adjusted to the maximum, and the compressor 10 is controlled to continuously refrigerate without stopping.

[0095] Step S20: Collect the refrigerator compartment temperature Tc and the freezer compartment temperature Td. Based on the refrigerator compartment temperature Tc and the freezer compartment temperature Td, determine when the refrigerator compartment temperature Tc and the freezer compartment temperature Td are stable, that is, when the refrigerator compartment temperature Tc and the freezer compartment temperature Td are almost unchanged. Record the refrigerator compartment temperature Tc and the freezer compartment temperature Td, and collect the inlet temperature Ti and the outlet temperature To of the first evaporator 50.

[0096] Step S30: Determine the first optimal opening degree of the first electronic expansion valve 40 based on the recorded freezer compartment temperature Td.

[0097] Step S40: Determine the second optimal opening degree of the second electronic expansion valve 80 based on the recorded refrigerator compartment temperature Tc.

[0098] In a further embodiment, step S30 includes:

[0099] Step S310: Control the opening of the first electronic expansion valve 40 to decrease the first preset opening value, and monitor the change of the freezer temperature Td.

[0100] Step S320: Determine whether the freezer temperature Td is no longer decreasing. If yes, proceed to step S330; otherwise, return to step S310 and continue to reduce the opening of the first electronic expansion valve 40 until the freezer temperature Td no longer decreases. The opening of the first electronic expansion valve 40 corresponding to the point where the freezer temperature Td no longer decreases is taken as the first optimal opening.

[0101] Step S330: Determine the current opening degree of the first electronic expansion valve 40 as the first optimal opening degree.

[0102] In a further embodiment, step S40 includes:

[0103] Step S410: Control the opening of the second electronic expansion valve 80 to decrease the second preset opening value, and monitor the change of the refrigerator compartment temperature Tc.

[0104] Step S420: Determine whether the refrigerator compartment temperature Tc is no longer decreasing. If yes, proceed to step S430; otherwise, return to step S410 and continue to reduce the opening of the second electronic expansion valve 80 until the refrigerator compartment temperature Tc no longer decreases. The opening of the second electronic expansion valve 80 corresponding to the point where the refrigerator compartment temperature Tc no longer decreases is set as the second optimal opening.

[0105] Step S430: Determine the current opening degree of the second electronic expansion valve 80 as the second optimal opening degree.

[0106] You can execute steps S310 to S330 first, or you can execute steps S410 to S430 first; there is no restriction on the execution order.

[0107] In step S50, the opening of the first electronic expansion valve 40 is maintained at the first optimal opening, and the opening of the second electronic expansion valve 80 is maintained at the second optimal opening.

[0108] Step S60: Determine the optimal refrigerant charge based on the temperature difference between the outlet temperature To and the inlet temperature Ti of the first evaporator 50.

[0109] In one embodiment, step S60 includes:

[0110] Step S610: Monitor the outlet temperature To and inlet temperature Ti of the first evaporator 50.

[0111] Step S620: Determine whether the temperature difference between the outlet temperature To and the inlet temperature Ti of the first evaporator 50 is greater than or equal to the preset value Ts. If yes, proceed to step S630; otherwise, proceed to step S640.

[0112] Step S630: Take the current refrigerant charge as the optimal charge.

[0113] In step S640, the refrigerant charge is reduced by a preset amount, and the process returns to step S620 until the temperature difference between the outlet temperature To and the inlet temperature Ti of the first evaporator 50 is less than a preset value Ts. The refrigerant charge when the temperature difference between the outlet temperature To and the inlet temperature Ti of the first evaporator 50 is less than the preset value Ts is taken as the optimal charge amount.

[0114] The adjustment principle of the refrigerant charge determination method in this embodiment is basically the same as that of the refrigerant charge determination method for the refrigerator refrigeration system 100 with only a first evaporator 50 described above. The key differences are: 1. Since this embodiment includes a first evaporator 50 and a second evaporator 70, meaning the refrigerator compartment and freezer compartment are refrigerated independently, adjusting the opening of the first electronic expansion valve 40 and the second electronic expansion valve 80 only requires separate adjustment. Specifically, the first optimal opening of the first electronic expansion valve 40 is adjusted based on the temperature change in the freezer compartment. At this time, the second electronic expansion valve 80 is closed, and the refrigerator refrigeration system 100 only cools the freezer compartment. Similarly, the second optimal opening of the second electronic expansion valve 80 is adjusted based on the temperature of the refrigerator compartment. At this time, the first electronic expansion valve 40 is closed, and the refrigerator refrigeration system 100 only cools the refrigerator compartment. 2. Since the temperature difference between the inlet and outlet of the refrigeration evaporator is a better indicator of refrigerant sufficiency, when adjusting the refrigerant charge, only the temperature difference between the inlet and outlet of the first evaporator 50 needs to be considered, and the temperature difference between the inlet and outlet of the second evaporator 70 no longer needs to be considered.

[0115] This embodiment also provides a method for determining the refrigerant charge of a refrigerator refrigeration system 100 equipped with a refrigeration evaporator and a freezing evaporator. After adjusting the first optimal opening degree of the first electronic expansion valve 40 and the second optimal opening degree of the second electronic expansion valve 80 respectively, the optimal charge is adjusted according to the change of the inlet and outlet temperature difference of the first evaporator 50. When the refrigerant charge is taken as the optimal charge, it can be ensured that it is the minimum charge to maintain the refrigeration effect, without causing resource waste and helping to save costs.

[0116] Figure 7 This is a schematic diagram of the structure of a controller 200 according to an embodiment of the present invention. Figure 7As shown, the present invention also provides a controller 200, which includes a memory 220 and a processor 210. The memory 220 stores a control program 222, which, when executed by the processor 210, is used to implement the refrigerant charge determination method in any of the above embodiments or combinations of embodiments. The processor 210 may be a central processing unit (CPU), a digital processing unit, etc. The processor 210 sends and receives data through a communication interface. The memory 220 is used to store the program executed by the processor 210. The memory 220 can be any medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, or it may be a combination of multiple memories 220. The above-described computational program can be downloaded from a computer-readable storage medium to a corresponding computing / processing device or downloaded to a computer or external storage device via a network (e.g., the Internet, a local area network, a wide area network, and / or a wireless network).

[0117] It should be noted that the controller 200 is not the refrigerator controller 200, but rather the controller 200 of the refrigerant charge adjustment equipment. Before the refrigerator is charged with refrigerant, the optimal charge amount is determined in advance by the refrigerant charge adjustment equipment.

[0118] The controller 200 can determine the optimal opening degree of the first electronic expansion valve 40 by monitoring the refrigerator compartment temperature Tc and the freezer compartment temperature Td. Then, it maintains the first electronic expansion valve 40 at the optimal opening degree and determines the optimal refrigerant charge amount by using the inlet temperature Ti and outlet temperature To of the first evaporator 50. This provides a method for determining the refrigerant charge amount of a refrigerator refrigeration system 100 that performs throttling and heat exchange through the first electronic expansion valve 40 and the heat exchange tube 30, respectively, so that the refrigerator refrigeration system 100 can have the optimal refrigerant charge amount.

[0119] Therefore, those skilled in the art should recognize that although numerous exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Thus, the scope of the present invention should be understood and construed as covering all such other variations or modifications.

Claims

1. A method for determining the refrigerant charge amount for a refrigerator refrigeration system, the refrigerator refrigeration system comprising a compressor, a condenser, a heat exchange tube, a first electronic expansion valve, a first evaporator, and a return gas pipe connected in series and forming a loop, wherein the first evaporator is disposed in the freezer compartment, the heat exchange tube is in contact with the return gas pipe to exchange heat with the return gas pipe, and the refrigerator refrigeration system controls the refrigerant flow rate through the first electronic expansion valve, characterized in that... The method includes: Adjust the opening of the first electronic expansion valve to the maximum to control the compressor to continuously refrigerate without stopping; Collect the refrigerator compartment temperature and the freezer compartment temperature. When the refrigerator compartment temperature and the freezer compartment temperature are stable, record the refrigerator compartment temperature and the freezer compartment temperature. Also collect the inlet temperature and the outlet temperature of the first evaporator. The optimal opening degree of the first electronic expansion valve is determined based on the recorded refrigerator compartment temperature and the freezer compartment temperature; The opening degree of the first electronic expansion valve is controlled to be maintained at the optimal opening degree; The optimal refrigerant charge is determined based on the temperature difference between the outlet and inlet temperatures of the first evaporator. The step of determining the optimal opening of the first electronic expansion valve based on the recorded refrigerator compartment temperature and the freezer compartment temperature includes: The opening degree of the first electronic expansion valve is controlled to decrease by a preset opening value, and the changes in the temperature of the refrigerator compartment and the temperature of the freezer compartment are monitored. Determine whether the temperature of the refrigerator compartment and the temperature of the freezer compartment are no longer decreasing. If so, determine that the current opening of the first electronic expansion valve is the optimal opening. Otherwise, continue to reduce the opening of the first electronic expansion valve until the temperature of the refrigerator compartment and the temperature of the freezer compartment no longer decrease, and take the opening of the first electronic expansion valve corresponding to the point when the temperature of the refrigerator compartment and the temperature of the freezer compartment no longer decreases as the optimal opening.

2. The method for determining the refrigerant charge amount according to claim 1, characterized in that, The step of further reducing the opening of the first electronic expansion valve includes: Continue to control the opening of the first electronic expansion valve to decrease by a preset value.

3. The method for determining the refrigerant charge amount according to claim 1, characterized in that, The steps for determining the optimal refrigerant charge based on the temperature difference between the outlet and inlet temperatures of the first evaporator include: Monitor the outlet and inlet temperatures of the first evaporator; Determine whether the temperature difference between the outlet temperature and the inlet temperature of the first evaporator is greater than or equal to a preset value. If so, take the current refrigerant charge as the optimal charge. Otherwise, the refrigerant charge will be reduced by a preset amount until the temperature difference between the outlet and inlet temperatures of the first evaporator is less than the preset value, and the refrigerant charge when the temperature difference between the outlet and inlet temperatures of the first evaporator is less than the preset value will be taken as the optimal charge amount.

4. The method for determining the refrigerant charge amount according to any one of claims 1-3, characterized in that, The steps of controlling the opening of the first electronic expansion valve to decrease by a preset opening value include: The regulating motor controlling the first electronic expansion valve decreases by a preset number of steps.

5. A method for determining the refrigerant charge amount for a refrigerator refrigeration system, the refrigerator refrigeration system comprising a compressor, a condenser, a heat exchange tube, a first electronic expansion valve, a first evaporator, and a return gas pipe connected in series and forming a loop, the first evaporator being disposed in the freezer compartment, the heat exchange tube being in contact with the return gas pipe for heat exchange, the refrigerator refrigeration system controlling the refrigerant flow rate through the first electronic expansion valve, and the refrigerator refrigeration system further comprising: A refrigeration branch is connected in parallel to both ends of a freezing branch. The refrigeration branch includes a second evaporator and a second electronic expansion valve connected in series. The second evaporator is a refrigeration evaporator installed in the refrigeration compartment. The freezing branch includes a first evaporator and a first electronic expansion valve connected in series. The method is characterized by comprising: Adjust the opening of the first electronic expansion valve and the second electronic expansion valve to the maximum to control the compressor to continuously refrigerate without stopping; Collect the refrigerator compartment temperature and the freezer compartment temperature. When the refrigerator compartment temperature and the freezer compartment temperature are stable, record the refrigerator compartment temperature and the freezer compartment temperature. Also collect the inlet temperature and the outlet temperature of the first evaporator. The first optimal opening degree of the first electronic expansion valve is determined based on the recorded freezer temperature; The second optimal opening degree of the second electronic expansion valve is determined based on the recorded refrigerator compartment temperature; The opening degree of the first electronic expansion valve is controlled to be maintained at the first optimal opening degree, and the opening degree of the second electronic expansion valve is maintained at the second optimal opening degree; The optimal refrigerant charge is determined based on the temperature difference between the outlet and inlet temperatures of the first evaporator. The step of determining the first optimal opening degree of the first electronic expansion valve based on the recorded freezer compartment temperature includes: The opening degree of the first electronic expansion valve is controlled to decrease by a first preset opening value, and the change in the temperature of the freezer compartment is monitored; Determine whether the temperature of the freezer compartment is no longer decreasing; if so, determine that the current opening of the first electronic expansion valve is the first optimal opening. Otherwise, continue to reduce the opening of the first electronic expansion valve until the freezer temperature no longer decreases, and take the opening of the first electronic expansion valve corresponding to the point when the freezer temperature no longer decreases as the first optimal opening.

6. The method for determining the refrigerant charge amount according to claim 5, characterized in that, The step of determining the second optimal opening degree of the second electronic expansion valve based on the recorded refrigerator compartment temperature includes: The opening degree of the second electronic expansion valve is controlled to decrease to a second preset opening value, and the change in the temperature of the refrigerator compartment is monitored. Determine whether the temperature of the refrigerator compartment is no longer decreasing; if so, determine that the current opening of the second electronic expansion valve is the second optimal opening. Otherwise, continue to reduce the opening of the second electronic expansion valve until the temperature of the refrigerator compartment no longer decreases, and set the opening of the second electronic expansion valve corresponding to the point when the temperature of the refrigerator compartment no longer decreases as the second optimal opening.

7. The method for determining the refrigerant charge amount according to claim 5, characterized in that, The steps for determining the optimal refrigerant charge based on the temperature difference between the outlet and inlet temperatures of the first evaporator include: Monitor the outlet and inlet temperatures of the first evaporator; Determine whether the temperature difference between the outlet temperature and the inlet temperature of the first evaporator is greater than or equal to a preset value. If so, take the current refrigerant charge as the optimal charge. Otherwise, the refrigerant charge will be reduced by a preset amount until the temperature difference between the outlet and inlet temperatures of the first evaporator is less than the preset value, and the refrigerant charge when the temperature difference between the outlet and inlet temperatures of the first evaporator is less than the preset value will be taken as the optimal charge amount.

8. A controller comprising a memory and a processor, the memory storing a control program, which, when executed by the processor, is used to implement the method for determining the refrigerant charge amount according to any one of claims 1-7.

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