Refrigerator and control method thereof

Abstract

This invention provides a refrigerator and a method for controlling it. The refrigerator includes a refrigeration system and a heating device. The refrigeration system includes a compressor, a condenser, a first throttling device, and a first evaporator, all connected in a circulating pipeline. The pipeline includes a first pipe section and a second pipe section. The outlet of the condenser is connected to the inlet of the first evaporator via the first pipe section, the first throttling device, and the second pipe section. The heating device is configured to controllably heat the first pipe section, the second pipe section, and / or the first throttling device, thereby regulating the refrigerant flow rate through the first throttling device by controlling the heating device. Because of the heating device, the refrigerant flow rate through the first throttling device can be regulated by controlling the power of the heating device, eliminating the need for a low-pressure liquid receiver; and eliminating abnormal noise from the low-pressure liquid receiver.

Description

Technical Field

[0001] This invention relates to the field of frozen and refrigerated storage technology, and in particular to a refrigerator and a refrigerator control method. Background Technology

[0002] like Figure 1 As shown, Figure 1 A refrigeration system for refrigerators is provided. This refrigeration system is an existing and mature refrigeration system used in refrigerators. The throttling element is a capillary tube. High-temperature and high-pressure gaseous refrigerant is discharged from the compressor 81 and enters the condenser 82 for condensation. Then it enters the anti-condensation pipe 83 for further condensation. The refrigerant is subcooled (about 1-5K) when it is output from the anti-condensation pipe. After passing through the dryer filter, it enters the capillary tube 84 for throttling and becomes a low-temperature and low-pressure two-phase refrigerant. Then it enters the evaporator 85 for evaporation. When the refrigeration system is running stably, the refrigerant output from the evaporator outlet is almost completely evaporated without overheating. It then enters the heat exchange return pipe through the low-pressure liquid receiver 86. The heat exchange return pipe exchanges heat with the capillary tube. The temperature of the refrigerant output from the heat exchange return pipe is close to the ambient temperature. Then it enters the compressor suction port, and the cycle repeats. The capillary tube's regulation of refrigerant flow is briefly explained as follows: When the refrigerant flow through the capillary tube is small, the refrigerant at the evaporator outlet becomes overheated. The liquid refrigerant stored in the low-pressure receiver gradually vaporizes and enters the system circulation. The amount of liquid refrigerant stored in the low-pressure receiver gradually decreases, while the amount of refrigerant in the condenser gradually increases. The condensing pressure in the condenser (which is basically equal to the refrigerant pressure before throttling) and the subcooling of the refrigerant before throttling gradually increase, causing the refrigerant flow through the capillary tube to gradually increase until it reaches stable operation. At this point, the refrigerant output from the evaporator outlet is almost completely evaporated without overheating, the amount of liquid refrigerant stored in the low-pressure receiver remains almost constant, and the refrigerant flow through the capillary tube also remains almost constant. When the refrigerant flow rate through the capillary tube is too high, the refrigerant at the evaporator outlet carries liquid. Due to the gas-liquid separation function of the low-pressure liquid receiver, the liquid refrigerant stored in the low-pressure liquid receiver gradually increases, the amount of refrigerant in the condenser gradually decreases, and the condensing pressure in the condenser (basically equal to the refrigerant pressure before throttling) and the subcooling before throttling gradually decrease. This causes the refrigerant flow rate through the capillary tube to gradually decrease until it reaches stable operation. At this point, the refrigerant output from the evaporator outlet is almost completely evaporated without overheating, the amount of liquid refrigerant stored in the low-pressure liquid receiver remains almost constant, and the refrigerant flow rate through the capillary tube also remains almost constant.

[0003] like Figure 2 As shown, Figure 2A refrigeration system is provided, which is an existing and mature refrigeration system used in commercial refrigeration and freezing. The throttling element is an expansion valve. After the high-temperature and high-pressure refrigerant is discharged from the compressor 91, it enters the condenser 92 for condensation, and then enters the high-pressure liquid receiver 93. It then passes through the solenoid valve 94 and the dryer filter in sequence before entering the expansion valve 95 for throttling, becoming a low-temperature and low-pressure two-phase refrigerant. It then enters the evaporator 96 to absorb heat and evaporate. The refrigerant output from the evaporator outlet is a slightly superheated (superheat degree of about 3-7K) gaseous refrigerant, which then enters the compressor suction port through the return pipe, and the cycle repeats. Commonly used expansion valves include thermostatic expansion valves and electronic expansion valves. Thermostatic expansion valves have a built-in temperature sensor located at the evaporator outlet to detect the superheat at that point. Increased superheat leads to a larger valve opening, while decreased superheat leads to a smaller valve opening. Electronic expansion valves use temperature and pressure sensors located at the evaporator outlet to detect superheat. Increased superheat leads to a larger valve opening, while decreased superheat leads to a smaller valve opening. The adjustment mechanism of the expansion valve to refrigerant flow is briefly explained as follows: When the refrigerant flow through the expansion valve is too small, the refrigerant superheat at the evaporator outlet increases, causing the expansion valve to open larger, resulting in a larger refrigerant flow through the valve. This continues until the refrigeration system is running stably, at which point the refrigerant flow through the expansion valve remains almost constant. Conversely, when the refrigerant flow through the expansion valve is too large, the refrigerant superheat at the evaporator outlet decreases, causing the expansion valve to open smaller, resulting in a smaller refrigerant flow through the valve. This continues until the refrigeration system is running stably, at which point the refrigerant flow through the expansion valve remains almost constant. Summary of the Invention

[0004] The inventors of this invention have discovered the following drawbacks of capillary throttling: A low-pressure liquid reservoir is installed at the evaporator outlet, which occupies space. Especially in special circumstances where space is limited, the reservoir may have nowhere to be placed, or its placement may cause other problems (e.g., when placed in the door of a refrigerator with a door-mounted ice-freezing function as proposed in this invention, it is difficult to place within the door space, or after placement, due to the slightly large diameter and low temperature of the reservoir, condensation may occur on the outer surface of the door, increasing cold loss). Currently, the low-pressure liquid reservoirs commonly used in refrigerators produce abnormal noise when the refrigerant flows during refrigeration system operation. If there are two parallel refrigeration circuits, and each evaporator outlet has a low-pressure liquid reservoir, when only one circuit is running, the liquid refrigerant in the other circuit's low-pressure liquid reservoir may be difficult to output into the circulating circuit, resulting in a refrigerant shortage in the circulating circuit and affecting its normal operation (e.g., slow cooling, low refrigeration efficiency).

[0005] The expansion valve throttling method has the following drawbacks: In applications with small cooling capacity (such as below 100W, or even below 50W), the required expansion valve diameter is too small (approximately 0.4mm), making mass production difficult (currently, the diameter of mature mass-produced expansion valves is 0.8mm or larger); in applications with small cooling capacity, the required expansion valve diameter is small (e.g., 0.4mm), and the opening is even smaller during normal operation, making it extremely prone to blockage due to impurities. Even if a dryer filter is installed before the expansion valve, blockage cannot be guaranteed (at least the inlet of the expansion valve still needs to be welded, and welding easily produces fine impurities), affecting the normal operation of the refrigeration system; the expansion valve is expensive; if an electronic expansion valve is used, its reset and operation noise is loud; the expansion valve occupies space, especially in special applications, where there may be nowhere to place it (such as the ice-making compartment of the refrigerator with ice-making function proposed in this application, where space is very compact; once placed inside the door foam layer, if it is an electronic expansion valve, its vibration and noise during operation are amplified; and whether it is an electronic expansion valve or a thermostatic expansion valve, it cannot be repaired once it is buried inside the foam layer).

[0006] Based on this, the present invention provides a refrigerator and a refrigerator control method, which can solve how to adjust the refrigerant flow rate through a throttling element, especially how to adjust the refrigerant flow rate of a throttling device with a fixed flow orifice.

[0007] On one hand, the present invention provides a refrigerator, including a refrigeration system and a heating device. The refrigeration system includes a compressor, a condenser, a first throttling device, and a first evaporator that are circulated and connected by a pipeline. The pipeline includes a first pipe section, a second pipe section, and a first return gas pipe section. The outlet of the condenser is connected to the inlet of the first evaporator through the first pipe section, the first throttling device, and the second pipe section. The first return gas pipe section is disposed between the outlet of the first evaporator and the inlet of the compressor.

[0008] The heating device is configured to controllably heat at least a portion of the first pipe section, the second pipe section, the first throttling device, the first evaporator, and / or the first return gas pipe section, so as to regulate the refrigerant flow through the first throttling device by controlling the heating device.

[0009] Optionally, the first return gas pipe section includes a return gas heat exchange pipe section, the entire return gas heat exchange pipe section being thermally connected to the first throttling device or the first pipe section; when the heating device is configured to heat the first return gas pipe section, the heating device heats the return gas heat exchange pipe section, or the heating device heats the pipe section between the inlet of the return gas heat exchange pipe section and the outlet of the first evaporation device.

[0010] Optionally, the first return gas pipe section is thermally connected to the first throttling device or the first pipe section to control the heating device based on the superheat of the refrigerant at a preset position on the first return gas pipe section, the temperature of the refrigerant at a preset position on the first return gas pipe section, the temperature of the refrigerant at the outlet of the first evaporator, or the superheat of the refrigerant at the outlet of the first evaporator.

[0011] Optionally, the condensing device includes a first condenser and a second condenser connected in series, and the refrigeration system further includes a high-pressure liquid storage tank disposed between the first condenser and the second condenser;

[0012] The first pipe section includes a first sub-section, a second sub-section, and a drying filter disposed between the first sub-section and the second sub-section. The heating device is configured to controllably heat the first sub-section, the second sub-section, and / or the drying filter; or, the heating device is configured to controllably heat a first return gas pipe section to heat the first pipe section or the first throttling device through the first return gas pipe section.

[0013] Optionally, the refrigerator further includes a cabinet and a door, and the refrigeration system further includes an on / off flow direction control device and a second evaporator; the compressor, the condenser, the on / off flow direction control device, and the second evaporator are installed in the cabinet; the inlet of the second evaporator is connected to the outlet of the condenser, and the outlet of the second evaporator is connected to the inlet of the compressor; the on / off flow direction control device is configured to control the on / off of the pipeline between the condenser and the first evaporator, and the on / off of the pipeline between the condenser and the second evaporator; the first throttling device and the first evaporator are disposed in the door;

[0014] The first throttling device is a flow regulating device with a fixed flow outlet.

[0015] On the other hand, the present invention also provides a control method for any of the above-mentioned refrigerators, comprising:

[0016] Detect the superheat or subcooling of the refrigerant at a preset location in the refrigeration system;

[0017] The heating device is controlled according to the degree of supercooling or the degree of superheating.

[0018] Optionally, the superheat value is obtained by detecting the superheat of the refrigerant at a preset location in the refrigeration system;

[0019] Controlling the heating device based on the supercooling or the superheat includes:

[0020] Determine whether the superheat value is greater than a first preset value, and determine whether the superheat value is less than a second preset value, wherein the first preset value is greater than or equal to the second preset value;

[0021] When the superheat value is greater than a first preset value, the heating power of the heating device is reduced;

[0022] When the superheat value is less than the second preset value, the heating power of the heating device is increased;

[0023] When the superheat value is between the second preset value and the first preset value, the heating power of the heating device is kept constant.

[0024] Optionally, the superheat value is obtained by detecting the superheat of the refrigerant at a preset location in the refrigeration system;

[0025] Controlling the heating device according to the supercooling or the superheat includes performing PID control based on the superheat value, so that the superheat value is between a second preset value and a first preset value, wherein the first preset value is greater than or equal to the second preset value.

[0026] Optionally, the refrigerator control method also includes:

[0027] A first temperature value is obtained by detecting the temperature at the inlet of the first evaporator, and a second temperature value is obtained by detecting the temperature of the refrigerant at a preset position in the refrigeration system. The superheat value of the refrigerant at the preset position in the refrigeration system is the difference between the second temperature value and the first temperature value.

[0028] Optionally, detecting the superheat of the refrigerant at a preset location in the refrigeration system involves detecting the superheat of the refrigerant at a preset location on the first return gas pipe section. The refrigerator control method further includes:

[0029] Obtain the distance between a preset position on the first return gas pipe section and the inlet of the first return gas pipe section, and determine the first preset value and the second preset value based on the distance;

[0030] The first preset value and the second preset value are arranged such that the superheat of the refrigerant at the outlet of the first evaporator is less than the third preset value.

[0031] Optionally, the condensing device includes a first condenser, and the refrigerator further includes a condensing fan for causing airflow to pass through the first condenser;

[0032] When the superheat value is greater than the first preset value, the heating power of the heating device is reduced according to a preset rule until the heating device stops working; and when the superheat value continues to be greater than the first preset value, the speed of the condenser fan is reduced.

[0033] In the refrigerator and refrigerator control method of the present invention, because a heating device is provided, the flow rate of the refrigerant flowing through the first throttling device can be adjusted by controlling the power of the heating device, and the low-pressure liquid storage tank can be eliminated; and there is no abnormal noise from the low-pressure liquid storage tank.

[0034] Furthermore, in the refrigerator and refrigerator control method of the present invention, compared with the addition of an ice-making liquid storage tank: when the refrigeration / freezing reaches a suitable temperature and no refrigeration is needed, but the ice-making circuit needs refrigeration, the electric switching valve connects the ice-making circuit for refrigeration; however, at this time, since the compressor is still working, the refrigerant in the refrigeration / freezing evaporator will still be drawn into the compressor and enter the ice-making cycle circuit, resulting in more and more refrigerant in the ice-making cycle circuit, which will cause the system to deviate from normal operation: such as condensation / frost on the low-pressure connecting hose, or even liquid in the compressor suction. While this can be improved by adding a liquid receiver at the outlet of the ice evaporator, there are several drawbacks: The liquid receiver needs to be large enough to hold excess refrigerant (the ice evaporator is relatively small compared to the refrigerator evaporator, especially the freezer evaporator), but the space inside the door is very limited, making it difficult to fit a liquid receiver of sufficient size. When the refrigerator or freezer recools, if the ice-making circuit is also operating simultaneously, the excess refrigerant stored in the liquid receiver at the ice evaporator outlet cannot escape, leading to a refrigerant shortage in the refrigerator or freezer cycle, significantly reducing cooling efficiency and causing slow cooling. Even if the ice-making circuit is not operating, the excess refrigerant stored in the liquid receiver at the ice evaporator outlet can slowly re-enter the refrigerator or freezer cycle when the refrigerator or freezer recools, but this still results in slow cooling and repeated refrigerant migration, unnecessarily increasing power consumption and reducing energy efficiency. Furthermore, the liquid receivers commonly used in refrigerators generate abnormal noise during refrigeration system operation. Since these receivers are placed inside the door, users are more likely to perceive this noise, severely impacting the user experience.

[0035] This invention, by adjusting the refrigerant flow rate through a heating device, can reduce or even eliminate the need for an ice-making reservoir. Furthermore, since the ice-making circuit requires very little cooling capacity (approximately 30-40W), and electric heating regulates the refrigerant flow rate by adjusting the refrigerant subcooling (or the amount of gaseous refrigerant it carries), only a few watts of power are needed. Especially under normal ambient temperatures, it is almost never needed or only requires 1-2W of power, with slightly higher power required only in high-temperature environments. Compared to adding an ice-making reservoir, this method is more energy-efficient, the cooling rate for refrigeration or freezing is almost unaffected, and there is no abnormal noise.

[0036] Furthermore, in the refrigerator and its control method of the present invention, compared to using a throttling element with flow regulation function (such as an electronic expansion valve or a thermal expansion valve, which works better when used in conjunction with a high-pressure liquid receiver) in the ice-making circuit: if an expansion valve is to be used in the ice-making circuit, the required expansion valve diameter is too small (approximately 0.4 mm) due to the small cooling capacity of the ice-making circuit, making it difficult to manufacture or mass-produce (currently, mature mass-produced electronic expansion valves all have diameters of 0.8 mm or larger); moreover, when the ice-making circuit is working stably, the expansion valve has a very small opening (the flow rate is relatively too large when fully open), allowing even smaller amounts of impurities to pass through, making it extremely easy to clog and affecting performance. The ice-making circuit operates normally; however, the flow rate of the capillary tube is regulated by electric heating. The capillary tube can be of standard diameter (length adjusted / increased as needed), and it is less prone to clogging. Valve components are expensive, while capillary tubes and electric heating are inexpensive. The electronic expansion valve generates significant noise during reset and operation (compared to the capillary tube), and its placement on the door makes the noise more noticeable and unacceptable to users. The expansion valve, located inside the ice-making room, occupies space (in fact, there's nowhere else to place it, as the ice-making room is very compact). If placed within the foam layer, it would be impossible to maintain, and the vibration and noise from the electronic expansion valve would be amplified, making it unacceptable to users. The capillary tube in this application is embedded within the door body, thus avoiding this problem.

[0037] 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

[0038] 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:

[0039] Figure 1 This is a schematic structural diagram of a refrigeration system in a refrigerator in the prior art;

[0040] Figure 2 This is a schematic structural diagram of a refrigeration system in a refrigerator in the prior art;

[0041] Figure 3 This is a schematic structural diagram of a refrigerator's refrigeration system according to an embodiment of the present invention;

[0042] Figure 4 This is a schematic structural diagram of a refrigerator's refrigeration system according to an embodiment of the present invention;

[0043] Figure 5 This is a schematic structural diagram of a refrigerator according to an embodiment of the present invention;

[0044] Figure 6This is a schematic structural diagram of a refrigerator according to an embodiment of the present invention;

[0045] Figure 7 This is a schematic partial structural diagram of a refrigerator according to an embodiment of the present invention;

[0046] Figure 8 This is a schematic partial structural diagram of a refrigerator according to an embodiment of the present invention;

[0047] Figure 9 This is a schematic partial structural diagram of a refrigerator according to an embodiment of the present invention. Detailed Implementation

[0048] Figure 3 This is a schematic structural diagram of a refrigerator's refrigeration system according to an embodiment of the present invention. Figure 3 As shown and referenced Figures 4 to 9 This invention provides a refrigerator. The refrigerator includes a cabinet 10, a door 20, a refrigeration system, and a heating device 60. The cabinet 10 has storage compartments, such as a first storage compartment, a second storage compartment, and a third storage compartment. The first storage compartment can be a refrigerator compartment, with a storage temperature generally between 2°C and 10°C, preferably between 3°C and 8°C. The second storage compartment can be a freezer compartment, with a temperature range generally between -14°C and -22°C. The third storage compartment can be a variable temperature compartment, with its temperature adjustable as needed to store suitable food. The door 20 is configured to open and close the first storage compartment. The refrigerator also has a second storage compartment door for opening and closing the second storage compartment, and a third storage compartment door for opening and closing the third storage compartment. Both the second and third storage compartment doors can be drawer end covers. In some optional embodiments, the storage compartments may contain only the first and second storage compartments.

[0049] A refrigeration system can be used to provide cooling capacity in a refrigerator. For example, the refrigeration system may include a compressor 31, a condenser, a first throttling device 42, and a first evaporator 43, all connected via piping. The piping includes a first pipe section, a second pipe section, and a first return pipe section 45. The outlet of the condenser is connected to the inlet of the first evaporator 43 via the first pipe section, the first throttling device 42, and the second pipe section. The first return pipe section 45 is located between the outlet of the first evaporator 43 and the inlet of the compressor 31. A heating device 60 is configured to controllably heat at least a portion of the first pipe section, the second pipe section, the first throttling device 42, the first evaporator 43, and / or the first return pipe section 45, to regulate the refrigerant flow through the first throttling device 42 by controlling the heating device 60. Further, for example, the heating device 60 can be controlled based on the temperature, superheat, or subcooling of the refrigerant at a preset location in the refrigeration system. A low-pressure liquid receiver can be eliminated; and there is no abnormal noise from the low-pressure liquid receiver. The first throttling device 42 is a flow regulating device with a fixed flow orifice, such as a capillary tube, a throttling orifice, or a throttling short tube.

[0050] Furthermore, the heating device 60 can be controlled based on the superheat of the refrigerant at the outlet of the first evaporator 43. The superheat of the refrigerant at the outlet of the first evaporator 43 is detected, and a superheat value is obtained. When the superheat value is greater than a first preset value, the heating power of the heating device 60 is reduced until it is turned off, causing the refrigerant supercooling before the first throttling device 42 to increase, the flow rate of the first throttling device 42 to increase, and the refrigerant superheat at the outlet of the first evaporator 43 to decrease. When the superheat value is less than a second preset value, the heating power of the heating device 60 is increased, the refrigerant supercooling before the first throttling device 42 to decrease, and even the refrigerant to carry a small amount of gaseous refrigerant, the flow rate of the first throttling device 42 to decrease, and the refrigerant superheat at the outlet of the first evaporator 43 to increase. When the superheat value is between the second and first preset values, the heating power of the heating device 60 is kept constant, the refrigerant flow rate through the first throttling device 42 remains almost constant, and the refrigerant superheat at the outlet of the first evaporator 43 also remains almost constant, allowing for stable operation. Alternatively, the heating device 60 can be controlled according to the temperature of the refrigerant at the outlet of the first evaporator 43.

[0051] In some embodiments of the present invention, the first return gas pipe section 45 is thermally connected to the first throttling device 42 or the first pipe section. For example, the first return gas pipe section 45 includes a return gas heat exchange pipe section, the entire of which is thermally connected to the first throttling device 42 or the first pipe section. Further, when the heating device is configured to heat the first return gas pipe section 45, the heating device 60 heats the return gas heat exchange pipe section, for example, heating part or all of the return gas pipe section. Alternatively, when the heating device is configured to heat the first return gas pipe section 45, the heating device heats the pipe section between the inlet of the return gas heat exchange pipe section 45 and the outlet of the first evaporator 43. Optionally, when the heating device is configured to heat the first return gas pipe section 45, the heating device heats the pipe section between the inlet of the return gas heat exchange pipe section 45 and the outlet of the first evaporator 43, and simultaneously heats the return gas heat exchange pipe section 45. Further optionally, the refrigerator can control the heating device 60 according to the temperature or superheat of the refrigerant at a preset position on the first return gas pipe section 45. Preferably, the refrigerator can control the heating device 60 according to the temperature or superheat of the refrigerant at a preset position on the return gas heat exchange pipe section of the first return gas pipe section 45.

[0052] In some embodiments of the present invention, the condensing device includes a first condenser 321 and a second condenser connected in series. The refrigeration system also includes a high-pressure liquid receiver 39 disposed between the first condenser 321 and the second condenser. The first condenser 321 may be an air-cooled condenser, and the refrigerator also includes a condensing fan for directing airflow through the first condenser 321. The second condenser may be a decondensation pipe 323, or the second condenser may include an internal condenser 322 installed within the refrigerator casing, and a decondensation pipe 323 connected in series with the internal condenser 322. The internal condenser 322 may be disposed close to the rear panel of the refrigerator. In some optional embodiments, the condensing device includes only the first condenser 321.

[0053] In some embodiments of the invention, the first pipe section includes a first sub-section, a second sub-section, and a drying filter 37 disposed between the first sub-section and the second sub-section, and the heating device 60 is configured to controllably heat the first sub-section, the second sub-section, and / or the drying filter 37. In some other embodiments of the invention, the heating device 60 is configured to controllably heat a first return gas pipe section 45 to heat the first pipe section or the first throttling device 42 through the first return gas pipe section 45.

[0054] In some embodiments of the present invention, such as Figure 4As shown, the refrigeration system also includes an on / off flow direction control device 36 and a second evaporator. The compressor 31, condenser, on / off flow direction control device 36, and second evaporator are installed in the housing. The inlet of the second evaporator is connected to the outlet of the condenser, and the outlet of the second evaporator is connected to the inlet of the compressor 31. The on / off flow direction control device 36 is configured to control the on / off of the pipeline between the condenser and the first evaporator 43, as well as the on / off of the pipeline between the condenser and the second evaporator. A first throttling device 42 and the first evaporator 43 are located in the door.

[0055] Furthermore, the refrigerator also includes an ice-making device 50, which is installed on the door 20. A first evaporator 43 is disposed within the door 20 or the ice-making device 50 and configured to provide cooling capacity to the ice-making device 50. In some alternative embodiments, an ice-making water device can be used instead of the ice-making device 50. In other alternative embodiments, a door storage space provided on the door 20 can be used instead of the ice-making device 50, that is, the first evaporator 43 is used to provide cooling capacity to the door storage space. Of course, two or three of the following can be simultaneously provided on the door 20: the ice-making device 50, the ice-making water device, and the door storage space. A second evaporator is used to cool the interior space of the refrigerator.

[0056] In the refrigerator of this embodiment, the first evaporator 43 can be used directly to make ice, cool water, or supply cooling to the door 20. Compared to supplying cooling to the door 20 through a long air duct, the refrigerator body 10 of this invention has better insulation (no air duct for ice making) and no air duct resistance loss, resulting in higher cooling efficiency. Compared to supplying cooling to the door 20 with low-temperature refrigerant, there is no need to insulate the pipes (insulating the pipes would make them thicker and take up more space), and the pipes are thinner, making installation easier. The first throttling device 42 is located on the door 20, avoiding the situation in the flexible capillary tube scheme where the flexible capillary tube may have cooled down by the time it enters the door 20, easily leading to condensation and loss of cooling capacity. This allows the ice-making capillary tube to use the most commonly used copper capillary tube, which has high precision and is easy to implement. The first throttling device 42 is entirely located inside the door 20, so the ice-making capillary tube is not subjected to force / deformation when the door is opened or closed, and the cooling performance is not affected. There is no significant difference in capillary flow rate or performance, making mass production easy and ensuring good control consistency.

[0057] In some embodiments of the present invention, the second sub-segment may include a first segment, a second segment 411, a liquid inlet connection segment 412, and a third segment. The first segment is disposed between the dryer filter 37 and the flow direction control device. The liquid inlet connection segment 412 is disposed between the housing 10 and the door 20. The second segment 411 is disposed between the first segment and the liquid inlet connection segment 412. The third segment is disposed between the liquid inlet connection segment 412 and the first throttling device 42. A return gas connection segment 46 and a housing-side return gas segment may be sequentially disposed between the first return gas pipe segment 45 and the compressor inlet. The return gas connection segment 46 is disposed between the door 20 and the housing 10 and connects the first return gas pipe segment 45 and the housing-side return gas segment. The housing-side return gas segment is connected to the inlet of the compressor 31. The heating device 60 is preferably an electric heating device 60 or other power adjustable heating device 60, used to heat the second segment 411, which may also be referred to as the heated segment.

[0058] In some embodiments of the present invention, the first throttling device 42 includes a capillary tube. In some optional embodiments, the first throttling device 42 further includes a throttling valve connected in series with the capillary tube, the throttling valve being disposed downstream of the capillary tube. Further, the door body 20 has an insulation layer, and the capillary tube of the first throttling device 42 can be disposed within the insulation layer of the door body 20, fully utilizing the insulation and fixing properties of the insulation layer, enabling the refrigerator to have better door body 20 cooling and ice-making functions. The inner diameter of the capillary tube is less than or equal to 0.8 mm. For example, the inner diameter of the capillary tube is between 0.65 mm and 0.75 mm. Preferably, the inner diameter of the capillary tube is about 0.66 mm or 0.70 mm, which ensures mass production consistency and prevents easy bending and collapse. The first return gas pipe section 45 is thermally connected to the capillary tube. The capillary tube exchanges heat with the first return gas pipe section 45, fully utilizing the heat generated during capillary throttling. This increases the temperature of the gas exiting the first return gas pipe section 45, preventing condensation at the low temperature of the return gas connection section 46 and improving the refrigerator's energy efficiency. Furthermore, both the capillary tube and the first return gas pipe section 45 are made of metal. The capillary tube is located within or in contact with the first return gas pipe section 45. The capillary tube is made of copper, and the first return gas pipe section 45 is made of aluminum or copper, preferably copper. Further, the first throttling device 42 may contain at least two capillary tubes, arranged in parallel and both thermally connected to the first return gas pipe section 45. Simultaneous heat exchange with the first return gas pipe section 45 by both tubes also reduces the heat exchange length of the first return gas pipe section 45.

[0059] In this embodiment of the invention, the following issues are avoided: In the flexible capillary tube scheme, the flexible capillary tube may have cooled down upon entering the door 20, easily leading to condensation and loss of cooling capacity. Furthermore, because the temperature of the flexible capillary tube entering the door 20 is low, the temperature of the return gas connection section 46 exiting the door 20 is also low, potentially causing condensation and loss of cooling capacity. In this invention, the liquid inlet connection section 412 of the second sub-tube of the first pipe section is higher than the ambient temperature. Therefore, there is no condensation or cooling capacity loss at the exposed portion between the door 20 and the housing 10. Due to the sufficient heat exchange between the first return gas pipe section 45 and the capillary tube, the refrigerant in the return gas connection section 46 is very close to or even higher than the ambient temperature, so there is no condensation or cooling capacity loss at the exposed portion between the door 20 and the housing 10.

[0060] The capillary tube and the first return gas pipe section 45 exchange heat within the door body 20, and both are made of metal, resulting in high heat exchange efficiency. A heat exchange length of approximately 1.5 meters (1-2 meters) is sufficient to ensure adequate heat exchange, making the return gas connection section 46 very close to or even higher than the ambient temperature. However, the flexible capillary tube solution uses a non-metallic material (metallic materials, when made flexible, are prone to breakage after numerous door openings and closings; refrigerators typically require 100,000 door openings and closings). Its heat exchange efficiency with the return gas pipe is extremely low, requiring a much longer length (estimated 20-100 meters) to ensure adequate heat exchange. The flexible capillary tube solution only exchanges heat at the door hinge, rendering it essentially ineffective. Currently, the door body 20 with ice-making function has a very thin insulation layer (30-35mm) in the main body (middle area), with only slightly thicker insulation layers (approximately 80mm) on the sides (viewed from above, with each side less than 10cm in size). Even assuming the flexible capillary design allows the flexible capillary section to extend from the door hinge into the door body 20 for heat exchange between non-metallic materials, achieving near-ambient temperature at the return pipe output would require a heat exchange length far exceeding 2 meters, potentially even 20 meters. The heat exchange section between the flexible capillary and the return pipe would need to be housed within a thick insulation layer (placing it in a thin layer would lead to condensation on the door body 20 and cold leakage). Space is limited, making a heat exchange length exceeding 2 meters difficult. This would require making the door thicker, unnecessarily increasing the refrigerator's size and resulting in a bulky door that is unacceptable to users. Furthermore, the contact between the flexible capillary and the flexible suction pipe loosens before and after entering the door hinge and door hinge when the door is opened and closed, affecting heat exchange efficiency and cooling performance. In this embodiment of the invention, the capillary heat exchange is independent of door opening and closing.

[0061] In some embodiments of the present invention, a throttling component may be provided between the flow direction control device and the second evaporator. The throttling component includes a second throttling device 331 and a third throttling device 332. The inlet of the second section 411 of the second sub-pipe of the first pipe section, the inlet of the second throttling device 331, and the inlet of the third throttling device 332 are respectively connected to the three outlets of the flow direction control device 36. The first evaporator 43 is a first evaporator, also referred to as an ice-making evaporator. The second evaporator includes a second evaporator 341 for supplying cooling to the first storage compartment and a third evaporator 342 for at least supplying cooling to the second storage compartment. The inlet of the second evaporator 341 is connected to the outlet of the second throttling device 331, and the outlets of the second evaporator 341 and the third throttling device 332 are both connected to the inlet of the third evaporator 342. A second return gas pipe section 38 may be provided between the outlet of the third evaporator 342 and the inlet of the compressor 31. Both the second throttling device 331 and the third throttling device 332 are capillary tubes. The second return gas pipe section 38 can exchange heat with the second throttling device 331 and / or the third throttling device 332.

[0062] Furthermore, the flow direction control device 36 may include a solenoid valve and a switching valve. The inlet of both the solenoid valve and the switching valve is connected to the outlet of the condensing unit, and the outlet of the solenoid valve is connected to the second section 411 of the second sub-pipe of the first pipe section. The switching valve may be a one-in-two-out electrically operated switching valve, with the inlet of the second throttling device 331 and the inlet of the third throttling device 332 connected to the two outlets of the switching valve, respectively. Optionally, the flow direction control device 36 may be a one-in-three-out electrically operated switching valve.

[0063] In some embodiments of the present invention, the liquid inlet connection section 412 of the second sub-pipe of the first pipe section is a first flexible hose, and the gas return connection section 46 is a second flexible hose. The flexible hoses facilitate the opening and closing of the door 20. The first flexible hose may be referred to as a high-pressure hose, a pressure-resistant hose, etc., and the second flexible hose may be referred to as a low-pressure hose. Further, the door 20 is rotatably mounted to the housing 10 via a hinge, which may be located at the upper end of the door 20. The lower end of the door 20 may be mounted to the housing 10 via another hinge. The hinge includes a hinge hole and a hinge shaft 11 inserted into the hinge hole; one of the hinge shaft 11 and the hinge hole is mounted to the housing 10, and the other is mounted to the door 20. The hinge shaft 11 has a through hole extending along its axial direction. For example, the hinge shaft 11 is mounted to the housing 10 via a horizontal mounting plate, and the door 20 has a hinge hole. Both the first flexible hose and the second flexible hose pass through the through hole. There's no need to insulate the pipes (insulating them would make the pipes thicker, taking up space and making it difficult to pass through the door hinge), and there's no cold air loss. The pipes are thin and can directly enter the door 20 from the top of the cabinet 10 through the hinge pin, resulting in a neat appearance and good consistency. The installation of the first and second flexible hoses does not affect the rotation of the door 20, thus not affecting the overall appearance of the refrigerator. The structural changes at the first and second flexible hoses are minimal, preventing pipe blockages or abrupt changes, and have virtually no impact on the refrigerator's performance.

[0064] The first flexible hose is a pressure-resistant hose, also known as a high-pressure hose. The material of the first flexible hose is nylon, Teflon, PTFE, or PFA, preferably Teflon. The outer diameter of the first flexible hose is less than or equal to 8 mm, and the inner diameter is less than or equal to 6 mm. Preferably, the outer diameter of the first flexible hose is less than or equal to 6 mm, and the inner diameter is less than or equal to 4 mm. For example, the outer diameter of the first flexible hose is less than or equal to 4.5 mm, and the inner diameter is less than or equal to 2.5 mm. Preferably, the outer diameter of the first flexible hose is 4 mm, and the inner diameter is 2 mm. It should be noted that the above diameters do not include the portions where the first flexible hose connects to the connectors; flaring may be required at these connections. The temperature of the refrigerant flowing through the first flexible hose remains essentially constant, and the first flexible hose may not require heat exchange with the second flexible hose for ease of installation and manufacturing. The second flexible hose can be referred to as a low-pressure hose. The first flexible hose has an appropriate inner diameter to ensure smooth refrigerant flow and high cooling efficiency. The first hose has an appropriate outer diameter, which allows it to have an appropriate wall thickness, so as to have appropriate deformation capacity and deformation recovery capacity, and also to have sufficient and appropriate pressure resistance.

[0065] In some embodiments of the present invention, the inventors discovered that after the first evaporator 43 is installed in the door 20, the return gas connection section 46, exposed between the door 20 and the cabinet 10, is prone to condensation, especially when the compressor 31 restarts after the third evaporator 342 in the freezer compartment defrosts. The reason for this phenomenon is that during defrosting of the third evaporator 342, due to the electric heating effect of the freezer compartment defrosting, the pressure and temperature of the refrigerant in the third evaporator 342 gradually increase, causing the refrigerant to migrate to the return gas connection section 46 and the first evaporator 43, resulting in an increase in the amount of refrigerant stored in the return gas connection section 46 and the first evaporator 43. When the compressor 31 restarts after defrosting, the low-pressure connecting hose at the hinge shaft and the portion at the top of the cabinet 10 (which can contact ambient air) has a lower temperature, leading to condensation. Based on this, a flow direction control device 48 is installed on the downstream side of the return gas connection section 46 to prevent the refrigerant from flowing to the first evaporator 43. The flow direction control device 48 is preferably a one-way valve, located on the return gas section on the cabinet side. Further, the return gas connection section 46 is connected to the suction port of the compressor 31 via a pipe installed on the cabinet 10, and the flow direction control device 48 is located on the pipe downstream of the return gas connection section 46. This prevents refrigerant from migrating from the cabinet side to the first evaporator 43, prevents an increase in the amount of refrigerant stored in the return gas connection section 46 and the first evaporator 43, and thus prevents condensation from forming in the return gas connection section 46 at the hinge shaft and the top of the cabinet 10 (which is in contact with ambient air) when the compressor 31 is restarted. By installing the flow direction control device 48, condensation or frost can be prevented from forming in the return gas connection section 46 when the temperature is low at startup, especially at the second flexible hose when refrigeration is first turned on.

[0066] In some embodiments of the present invention, a liquid storage bag 35 may be provided at the outlet of the second evaporator, that is, a liquid storage bag 35 may be provided at the outlet of the third evaporator 342, that is, the liquid storage bag 35 is located between the second return gas pipe section 38 and the third evaporator 342. The first evaporator 43 may include an ice-making section and a temperature maintenance section. The ice-making section may contact the ice box for ice making, and the temperature maintenance section may have fins and may be able to supply cooling to the ice-making chamber through forced circulation by the ice-making chamber fan to maintain the chamber temperature. For example, the two upper copper pipes of the first evaporator 43 are in contact with the ice box for ice making; the two lower copper pipes of the first evaporator 43 are finned and need to be supplied cooling to the ice-making chamber through forced circulation by the ice-making chamber fan to maintain the chamber temperature. A filter dryer 47 may be provided on the third section of the second sub-pipe of the first pipe section.

[0067] In this invention, when the refrigeration / freezing reaches a suitable temperature and refrigeration is not required, but the ice-making circuit requires refrigeration, the ice-making circuit is turned on for refrigeration. However, at this time, since the compressor 31 is still working, the refrigerant in the refrigeration / freezing evaporator will still be drawn into the compressor 31 and enter the ice-making cycle circuit, resulting in more and more refrigerant in the ice-making cycle circuit. It is possible that the refrigerant in the built-in condenser 322 and the anti-condensation pipe is completely liquid and cannot be contained (the built-in condenser 322 and the anti-condensation pipe are both subcooled sections). At this time, the high-pressure liquid storage tank 39 can contain the excess refrigerant. This prevents the built-in condenser 322 and the anti-condensation pipe from being unable to contain the excess refrigerant. In this case, there is too much subcooled section in the first condenser 321, so that the part actually used for condensation (gas condenses into liquid) is too little, which ultimately leads to too high pressure and a large increase in energy consumption.

[0068] This invention also provides a refrigerator control method, comprising: detecting the superheat or subcooling of the refrigerant at a preset location in the refrigeration system; and controlling the heating device 60 based on the subcooling or superheat.

[0069] Furthermore, the superheat value is obtained by detecting the superheat of the refrigerant at a preset location in the refrigeration system. Controlling the heating device 60 based on the superheat or supercooling includes: determining whether the superheat value is greater than a first preset value, and determining whether the superheat value is less than a second preset value, wherein the first preset value is greater than or equal to the second preset value; when the superheat value is greater than the first preset value, reducing the heating power of the heating device 60; when the superheat value is less than the second preset value, increasing the heating power of the heating device 60; and when the superheat value is between the second preset value and the first preset value, maintaining the heating power of the heating device 60 unchanged. When the detected superheat of the refrigerant at the preset location in the refrigeration system is the same as the superheat of the refrigerant at the outlet of the first evaporator 43, the range of the first and second preset values ​​can be 3–7 K, preferably 4–6 K. When the superheat of the refrigerant at a preset position in the refrigeration system is the same as the superheat of the refrigerant at a preset position on the return gas heat exchange pipe section of the first return gas pipe section 45, the range of the first preset value and the second preset value can be 5 to 15K, preferably 7 to 2K.

[0070] Furthermore, the condensing device includes a first condenser 321, and the refrigerator also includes a condensing fan to facilitate airflow through the first condenser 321. When the superheat value exceeds a first preset value, the heating power of the heating device 60 is reduced according to a preset rule until the heating device 60 stops working; and when the superheat value continues to exceed the first preset value, the speed of the condensing fan is reduced. The condensing fan is speed-adjustable, thereby regulating the airflow through the first condenser 321. Thus: once the electric heating of the heated section of the ice-making circulation loop is completely shut off, and the refrigerant flow is still insufficient, the speed of the condensing fan is reduced (or even the condensing fan is turned off), thereby reducing the condensing airflow, increasing the condensing pressure of the refrigerant in the first condenser 321, increasing the pressure before the ice-making capillary tube throttling, and increasing the flow rate of the ice-making capillary tube.

[0071] In some alternative embodiments of the invention, controlling the heating device 60 based on supercooling or superheat includes PID control based on a superheat value, such that the superheat value is between a second preset value and a first preset value, wherein the first preset value is greater than or equal to the second preset value.

[0072] In some embodiments of the present invention, the refrigerator control method further includes: detecting the temperature at the inlet of the first evaporator 43 to obtain a first temperature value, and detecting the temperature of the refrigerant at a preset position in the refrigeration system to obtain a second temperature value, wherein the superheat value of the refrigerant at the preset position in the refrigeration system is the difference between the second temperature value and the first temperature value. This can be detected by a first temperature sensor 71 and a second temperature sensor 72.

[0073] The refrigerator control method also includes obtaining the distance between a preset position on the first return gas pipe section 45 and the inlet of the first return gas pipe section 45, and determining a first preset value and a second preset value based on the distance. The further away from the outlet of the first evaporator 43, the larger both the first preset value and the second preset value can be. In some optional embodiments of the present invention, the first preset value and the second preset value are arranged such that the superheat of the refrigerant at the outlet of the first evaporator 43 is less than a third preset value. The third preset value can be 0. That is, the gaseous saturation point of the refrigerant (just without superheat) should be located on the first return gas pipe section 45 and not on the first evaporator 43, or just at the outlet of the first evaporator 43, so as to make full use of the heat exchange area of ​​the first evaporator 43.

[0074] In this application, those skilled in the art should recognize that the term "hose" as used refers to a flexible tube that has a certain deformation and recovery capability when subjected to external force, ensuring that it can undergo elastic deformation (e.g., a certain degree of torsion) as a whole when the door rotates, without substantially changing the cross-sectional area of ​​the fluid flow inside the tube. The first hose is a pressure-resistant hose, capable of withstanding a pressure above a first preset pressure value provided by the fluid inside it, and the second hose is also capable of withstanding a pressure above a second preset pressure value provided by the fluid inside it. The first preset pressure value may be greater than the second preset pressure value. For different refrigerants used in the refrigeration system, the first preset pressure value and the second preset pressure value may differ; for example, for R600a refrigerant, the first preset pressure value may be 2 MPa, and the second preset pressure value may be 1.5 MPa. Because the pressure generated by the refrigerant in the first hose is greater than the pressure generated in the second hose, the first hose may also be called a high-pressure hose, and the second hose may also be called a low-pressure hose.

[0075] 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 refrigerator, comprising a refrigeration system, characterized in that, It also includes a heating device. The refrigeration system includes a compressor, a condenser, a first throttling device, and a first evaporator that are circulated through a pipeline. The pipeline includes a first pipe section, a second pipe section, and a first return pipe section. The outlet of the condenser is connected to the inlet of the first evaporator through the first pipe section, the first throttling device, and the second pipe section. The first return pipe section is located between the outlet of the first evaporator and the inlet of the compressor. The heating device is configured to controllably heat at least a portion of the first pipe section, the second pipe section, the first throttling device, the first evaporator, and / or the first return gas pipe section, so as to regulate the refrigerant flow through the first throttling device by controlling the heating device; The refrigerator's control methods include: The superheat value is obtained by detecting the superheat of the refrigerant at a preset location in the refrigeration system; Controlling the heating device according to the superheat includes: Determine whether the superheat value is greater than a first preset value, and determine whether the superheat value is less than a second preset value, wherein the first preset value is greater than or equal to the second preset value; When the superheat value is greater than a first preset value, the heating power of the heating device is reduced; When the superheat value is less than the second preset value, the heating power of the heating device is increased; When the superheat value is between the second preset value and the first preset value, the heating power of the heating device is kept constant.

2. The refrigerator according to claim 1, characterized in that, The first return gas pipe section includes a return gas heat exchange pipe section, the entire return gas heat exchange pipe section being thermally connected to the first throttling device or the first pipe section; when the heating device is configured to heat the first return gas pipe section, the heating device heats the return gas heat exchange pipe section, and / or the heating device heats the pipe section between the inlet of the return gas heat exchange pipe section and the outlet of the first evaporation device.

3. The refrigerator according to claim 1, characterized in that, The first return gas pipe section is thermally connected to the first throttling device or the first pipe section to control the heating device according to the superheat of the refrigerant at a preset position on the first return gas pipe section, the temperature of the refrigerant at a preset position on the first return gas pipe section, the temperature of the refrigerant at the outlet of the first evaporator, or the superheat of the refrigerant at the outlet of the first evaporator.

4. The refrigerator according to claim 3, characterized in that, The condensation device includes a first condenser and a second condenser connected in series, and the refrigeration system also includes a high-pressure liquid storage tank disposed between the first condenser and the second condenser; The first pipe section includes a first sub-section, a second sub-section, and a drying filter disposed between the first sub-section and the second sub-section. The heating device is configured to controllably heat the first sub-section, the second sub-section, and / or the drying filter; or, the heating device is configured to controllably heat a first return gas pipe section to heat the first pipe section or the first throttling device through the first return gas pipe section.

5. The refrigerator according to claim 1, characterized in that, The refrigerator also includes a cabinet and a door. The refrigeration system further includes an on / off flow direction control device and a second evaporator. The compressor, the condenser, the on / off flow direction control device, and the second evaporator are installed in the cabinet. The inlet of the second evaporator is connected to the outlet of the condenser, and the outlet of the second evaporator is connected to the inlet of the compressor. The on / off flow direction control device is configured to control the on / off of the pipeline between the condenser and the first evaporator, as well as the on / off of the pipeline between the condenser and the second evaporator. The first throttling device and the first evaporator are located in the door. The first throttling device is a flow regulating device with a fixed flow outlet.

6. The refrigerator according to claim 1, characterized in that, The control method further includes: The superheat value is obtained by detecting the superheat of the refrigerant at a preset location in the refrigeration system; Controlling the heating device according to the superheat includes performing PID control based on the superheat value, so that the superheat value is between a second preset value and a first preset value, wherein the first preset value is greater than or equal to the second preset value.

7. The refrigerator according to claim 1 or 6, characterized in that, The control method further includes: A first temperature value is obtained by detecting the temperature at the inlet of the first evaporator, and a second temperature value is obtained by detecting the temperature of the refrigerant at a preset position in the refrigeration system. The superheat value of the refrigerant at the preset position in the refrigeration system is the difference between the second temperature value and the first temperature value.

8. The refrigerator according to claim 1 or 6, characterized in that, The control method further includes: The method for controlling the refrigerator further includes detecting the superheat of the refrigerant at a preset location in the refrigeration system, which involves detecting the superheat of the refrigerant at a preset location on the first return gas pipe section. Obtain the distance between a preset position on the first return gas pipe section and the inlet of the first return gas pipe section, and determine the first preset value and the second preset value based on the distance; or, The first preset value and the second preset value are arranged such that the superheat of the refrigerant at the outlet of the first evaporator is less than the third preset value.

9. The refrigerator according to claim 1, characterized in that, The control method further includes: The condensation device includes a first condenser, and the refrigerator also includes a condenser fan for causing airflow to pass through the first condenser; When the superheat value is greater than the first preset value, the heating power of the heating device is reduced according to a preset rule until the heating device stops working; and when the superheat value continues to be greater than the first preset value, the speed of the condenser fan is reduced.

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