Control method of a washing machine

Abstract

The control method of the laundry machine according to the embodiment of the present application, the laundry machine uses carbon dioxide as a washing solvent, the laundry machine includes a washing tub for containing laundry, a compressor for compressing gaseous carbon dioxide, a distillation tub for coexisting liquid carbon dioxide and gaseous carbon dioxide, and a washing flow path for connecting the washing tub, the compressor, and the distillation tub, and in the control method of the laundry machine, when an abnormal condition occurs and the laundry machine stops, a reset process for discharging carbon dioxide inside the washing tub is initiated, the reset process includes: a step of sensing the pressure inside the washing tub; a step of determining that the pressure inside the washing tub is higher than a first set pressure, and discharging liquid carbon dioxide; and after the discharging of the liquid carbon dioxide is completed, a step of recovering gaseous carbon dioxide inside the washing tub to the distillation tub until the pressure inside the washing tub reaches the first set pressure.

Description

Technical Field

[0001] This invention relates to a control method for a washing machine that uses carbon dioxide instead of water as a solvent for washing. Background Technology

[0002] In washing machines that use carbon dioxide as a solvent for washing, a high-pressure state is maintained inside the washing tub during the washing process. Therefore, if an abnormal situation occurs during operation, the washing machine will stop running and issue an alarm.

[0003] Furthermore, it is impossible to know the condition of the washing machine at the point when it stops running, so for safety reasons, request repair service or manually release the carbon dioxide through the exhaust pipe.

[0004] Abnormal situations that occur during operation can include sudden interruptions in operation due to malfunctions in the washing machine itself or power outages. In such cases, it becomes impossible to remove the laundry from the washing tub without waiting for a service center technician or risking the need to manually release carbon dioxide.

[0005] When the washing machine is stopped, it's impossible to determine which cycle it stopped in, resulting in the inability to expel all the carbon dioxide inside the tub, regardless of the condition within the tub. Consequently, carbon dioxide cannot be recovered, requiring replenishment after the waste carbon dioxide is expelled, leading to increased costs.

[0006] Prior technology: Korean Patent Publication No. 10-2023-0107498 (July 17, 2023) Summary of the Invention

[0007] Technical problems to be solved

[0008] This invention was made to improve the problems described above.

[0009] means of solving technical problems

[0010] According to an embodiment of the present invention, a control method for a washing machine is provided to achieve the objectives described above. The washing machine uses carbon dioxide as a washing solvent and includes a washing tub for containing laundry, a compressor for compressing gaseous carbon dioxide, a distillation tank where liquid and gaseous carbon dioxide coexist, and a washing channel connecting the washing tub, the compressor, and the distillation tank. In the control method, when an abnormal condition occurs and the washing machine stops operating, a reset process for discharging carbon dioxide from the washing tub is initiated. The reset process includes: a step of sensing the pressure inside the washing tub; a step of determining that the pressure inside the washing tub is higher than a first set pressure and discharging liquid carbon dioxide; and a step of recovering gaseous carbon dioxide from the washing tub to the distillation tank after the discharging of liquid carbon dioxide ends, until the pressure inside the washing tub reaches the first set pressure.

[0011] The feature is that the above-mentioned abnormal conditions include at least one of the power outage conditions or the above-mentioned washing machine malfunction conditions, and the above-mentioned reset process is performed at the time when the power is restored after the power outage is lifted or at the time when an alarm signal informing the washing machine of the malfunction is issued.

[0012] The characteristic is that the first set pressure is the minimum suction pressure that satisfies the allowable compression ratio of the compressor.

[0013] The feature is that the minimum inhalation pressure mentioned above is 2.5 bar.

[0014] The feature is that, during the period when the gaseous carbon dioxide inside the washing tub is recovered to the distillation tank, when the internal pressure of the washing tub drops to the first set pressure, the gaseous carbon dioxide recovery process ends, and the gaseous carbon dioxide remaining inside the washing tub is released into the atmosphere.

[0015] The feature is that when the internal pressure of the washing tub reaches the second set pressure, the reset process ends, and the second set pressure is lower than the first set pressure.

[0016] The feature is that when it is determined that the pressure inside the washing tub sensed after the above reset process has just been started is not higher than the first set pressure, the process of directly releasing the gaseous carbon dioxide remaining inside the washing tub into the atmosphere is carried out. When the pressure inside the washing tub reaches the second set pressure, the above reset process ends.

[0017] The feature is that, during the period when the gaseous carbon dioxide inside the washing tub is recovered to the distillation tank, when the internal pressure of the washing tub drops to the first set pressure, the gaseous carbon dioxide remaining inside the washing tub is naturally recovered to the storage tank through the natural recovery channel connecting the washing tub and the storage tank.

[0018] The characteristic is that the above-mentioned natural recycling process continues until the internal pressure of the washing tub remains constant.

[0019] The feature is that when the internal pressure of the aforementioned constant washing tub is higher than the second set pressure, the gaseous carbon dioxide inside the aforementioned washing tub is released into the atmosphere. When the internal pressure of the aforementioned washing tub reaches the aforementioned second set pressure, the aforementioned reset process ends. The aforementioned second set pressure is lower than the aforementioned first set pressure.

[0020] The feature is that when the internal pressure of the aforementioned constant washing tub is lower than the second set pressure, the vent provided on one side of the aforementioned washing tub is opened; when the internal pressure of the aforementioned washing tub reaches the aforementioned second set pressure, the aforementioned reset process ends, and the aforementioned second set pressure is lower than the aforementioned first set pressure.

[0021] The feature is that when the internal pressure of the aforementioned constant washing tub is higher than the second set pressure, the gaseous carbon dioxide inside the aforementioned washing tub is forcibly recovered to the aforementioned storage tank through the forced recovery flow channel connecting the aforementioned washing tub, the aforementioned compressor and the aforementioned storage tank, and the aforementioned second set pressure is lower than the aforementioned first set pressure.

[0022] The feature is that the forced recycling process continues until the pressure inside the washing tub reaches the second set pressure, and then the reset process ends.

[0023] The feature is that, during the period when the gaseous carbon dioxide inside the washing tub is recovered to the distillation tank, when the internal pressure of the washing tub drops to the first set pressure, the gaseous carbon dioxide inside the washing tub is forcibly recovered to the storage tank through a forced recovery channel connecting the washing tub, the compressor, and the storage tank.

[0024] The characteristic is that the forced recycling process continues until the pressure inside the washing tub reaches the second set pressure, and the reset process ends, wherein the second set pressure is lower than the first set pressure.

[0025] The characteristic is that the second set pressure mentioned above is atmospheric pressure.

[0026] Invention Effects

[0027] According to the control method of the washing machine according to the embodiment of the present invention, when an abnormal situation occurs during operation and the washing machine stops running, a reset process is initiated, which can quickly expel carbon dioxide located inside the washing tub, thereby having the advantage of being able to safely remove the clothes to be washed located inside the washing tub.

[0028] In addition, when the washing machine is not running, it can automatically either recover or release carbon dioxide based on the pressure in the washing tub, thus minimizing unnecessary carbon dioxide consumption. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of a washing machine using the control method according to an embodiment of the present invention.

[0030] Figures 2 to 8 This is a schematic diagram of the flow of carbon dioxide throughout the washing process.

[0031] Figure 9 This is a flowchart illustrating the reset process of a washing machine according to an embodiment of the present invention.

[0032] Figure 10 This is a system diagram illustrating a method for recovering gaseous carbon dioxide according to another embodiment of the present invention.

[0033] Figure 11 This is a flowchart illustrating the reset process of a washing machine according to another embodiment of the present invention.

[0034] Figure 12 This is a system diagram illustrating a method for recovering gaseous carbon dioxide according to yet another embodiment of the present invention.

[0035] Figure 13 This is a flowchart illustrating the reset process of a washing machine according to another embodiment of the present invention.

[0036] Figure 14 This is a flowchart illustrating the reset process of a washing machine according to another embodiment of the present invention. Detailed Implementation

[0037] The control method of a washing machine according to an embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

[0038] Figure 1 This is a schematic diagram of a washing machine using the control method according to an embodiment of the present invention.

[0039] Reference Figure 1 According to an embodiment of the present invention, the washing machine 10 is a waterless washing machine that uses carbon dioxide instead of water for washing.

[0040] In detail, the washing machine 10 according to the present invention includes a washing tub 11 for loading clothes to be washed and performing the entire (full) washing process, a vacuum pump 19 for discharging the gas remaining in the washing tub 11 and making the washing tub 11 a vacuum state, a distillation tank 14 for storing liquid carbon dioxide discharged from the washing tub 11, a compressor 13 for supplying gaseous carbon dioxide to the washing tub 11 or recovering gaseous carbon dioxide inside the washing tub 11 by operation, and a cooler 15 for condensing gaseous carbon dioxide into liquid carbon dioxide during the process of recovering gaseous carbon dioxide inside the washing tub 11.

[0041] Gaseous carbon dioxide and liquid carbon dioxide coexist inside the distillation tank 14. That is, at the bottom of the distillation tank 14, liquid carbon dioxide is filled to a predetermined level, and the internal space above it is filled with gaseous carbon dioxide.

[0042] Furthermore, the aforementioned constituent elements can be connected to each other via pipes to form a circulating flow channel. The pipes or channels constituting the circulating flow channel are described in detail below with reference to the accompanying drawings.

[0043] Figures 2 to 8 This is a schematic diagram of the flow of carbon dioxide throughout the washing process.

[0044] Reference Figure 2 The user opens the door of the washing tub 11, inserts the clothes to be washed, closes the door, and presses the wash start button. As a result, the vacuum pump 19, which is located in the exhaust channel 101 extending from one side of the washing tub 11, starts to operate, removing all the air and moisture present inside the washing tub 11, making the inside of the washing tub 11 a vacuum state.

[0045] Reference Figure 3 After the washing tub 11 is brought into a vacuum state, the differential pressure supply channel 102 connecting the distillation tank 14 and the washing tub 11 is opened, and the gaseous carbon dioxide stored in the distillation tank 14 is supplied to the washing tub 11 through the pressure difference. The supply of carbon dioxide through the pressure difference refers to the supply achieved by the natural flow of carbon dioxide from a high-pressure chamber to a low-pressure chamber. For reference, before the supply of gaseous carbon dioxide begins, the internal pressure of the distillation tank 14 is maintained at approximately 30 bar.

[0046] In detail, as carbon dioxide moves from the distillation tank 14 to the washing tank 11 through the pressure difference supply channel 102, the pressure inside the distillation tank 14 decreases, and the pressure inside the washing tank 11 increases. Furthermore, when the pressure in the distillation tank 14 and the washing tank 11 reach a pressure equilibrium state, the supply of gaseous carbon dioxide through the pressure difference supply channel 102 is stopped.

[0047] Regarding stopping the supply of gaseous carbon dioxide, the movement of carbon dioxide can be stopped naturally by achieving pressure equilibrium, or the movement of carbon dioxide can be manually stopped by opening or closing one or more switching valves (not shown) located in the aforementioned pressure difference supply channel 102. Once the flow of gaseous carbon dioxide stops, the supply of gaseous carbon dioxide can be considered terminated.

[0048] Reference Figure 4 When the supply of gaseous carbon dioxide is terminated, the gaseous carbon dioxide stored in the distillation tank 14 through the liquid supply channel 103 connecting the distillation tank 14, the compressor 13 and the washing tank 11 is phase-transformed into liquid carbon dioxide when passing through the distillation tank 14 and the cooler 15 and then supplied to the washing tank 11.

[0049] In detail, the liquid phase supply channel 103 may include a compressor suction channel 1031 connecting the inlet of the distillation tank 14 and the compressor 13, a compressor discharge channel 1032 connecting the outlet of the compressor 13 and the distillation tank 14, and a condensation channel 1033 extending from the end of the compressor discharge channel 1031 through the interior of the distillation tank 14 and the cooler 15 to the washing tank 11.

[0050] If the compressor 13 is started, the gaseous carbon dioxide inside the distillation tank 14 is drawn into the compressor 13 through the compressor intake channel 1031. Furthermore, the drawn-in carbon dioxide is compressed to a high temperature and high pressure by the compressor 13 and then flows into the distillation tank 14 through the compressor discharge channel 1032.

[0051] Furthermore, the aforementioned condenser channel 1033 extends in a state of being immersed in the liquid carbon dioxide inside the distillation tank 14, thereby releasing heat from the high-temperature, high-pressure gaseous carbon dioxide flowing along the condenser channel 1033 to the liquid carbon dioxide inside the distillation tank 14. As a result, a portion of the liquid carbon dioxide inside the distillation tank 14 is vaporized, and the temperature and pressure of the carbon dioxide flowing along the condenser channel 1033 decrease. Moreover, gaseous carbon dioxide is no longer released along the compressor channel 1031; instead, a portion of the liquid carbon dioxide is vaporized through heat exchange with the condenser channel 1033, so the complete depletion of gaseous carbon dioxide inside the distillation tank 14 is prevented.

[0052] On the other hand, the condensation channel 1033, which passes through the distillation tank 14, extends to the washing tub 11 after passing through the cooler 15. Therefore, the gaseous carbon dioxide flowing along the condensation channel 1033 releases heat to the outside when passing through the cooler 15, and is thus completely condensed into liquid carbon dioxide, which is supplied to the washing tub 11 (refer to the dashed arrow). Furthermore, when the internal pressure of the distillation tank 14 drops to approximately 12-15 bar, the supply of liquid carbon dioxide is stopped, and the washing process begins.

[0053] Reference Figure 5 ,like Figure 4 The process is shown to involve a washing cycle after the supply of gaseous and liquid carbon dioxide is terminated, followed by the discharge of contaminated liquid carbon dioxide from the washing tub 11 after the washing cycle is terminated.

[0054] In detail, after the washing process ends, the remaining liquid carbon dioxide is discharged into the distillation tank 14 through the liquid discharge channel 104 connecting the washing tank 11 and the distillation tank 14. At this time, a ventilation process is carried out simultaneously with the discharge of liquid carbon dioxide to supply gaseous carbon dioxide into the washing tank 11, so as to avoid the pressure drop inside the washing tank 11 during the discharge of liquid carbon dioxide, thereby delaying the discharge of liquid carbon dioxide.

[0055] In detail, the above-mentioned ventilation process is achieved through a ventilation channel 105 connecting the distillation tank 14, the compressor, and the washing tub 11. The ventilation channel 105 includes an intake-side ventilation channel 1051 connecting the intake port of the distillation tank 14 and the compressor 13, and an outlet-side ventilation channel 1052 connecting the outlet of the compressor 13 and the washing tub 11.

[0056] More specifically, once the ventilation process begins, the gaseous carbon dioxide inside the distillation tank 14 flows into the compressor 13 via the suction-side ventilation channel 1051 and is supplied to the washing tub 11 via the discharge-side ventilation channel 1052. As a result, even if liquid carbon dioxide is discharged into the distillation tank 14, there will be no pressure drop inside the washing tub 11. Furthermore, the ventilation process is stopped when all the liquid carbon dioxide inside the washing tub 11 is discharged.

[0057] Reference Figure 6 After the discharge of contaminated liquid carbon dioxide is completed, the gaseous carbon dioxide remaining in the distillation tank 14 is compressed and condensed to supply the liquid carbon dioxide back to the washing tank 11 for rinsing.

[0058] In detail, the supply process of liquid carbon dioxide used for rinsing is related to... Figure 4 The process for supplying liquid carbon dioxide is the same as described in the previous section, so the explanation of this is omitted.

[0059] Reference Figure 7 After the rinsing cycle ends, a process is performed similar to the process of discharging liquid carbon dioxide after the washing process to discharge the contaminated liquid carbon dioxide remaining in the washing tub 11 into the distillation tank 14.

[0060] In detail, the contaminated liquid carbon dioxide is discharged into the distillation tank 14 through the liquid phase discharge channel 14, while a ventilation process is carried out to supply gaseous carbon dioxide to the washing tank 11 through the air passage 105. This content is related to... Figure 5 The content described in the previous section is the same, so repeated explanations are omitted.

[0061] Reference Figure 8 After the discharge of contaminated liquid carbon dioxide is completed, a recovery process is carried out to recover the high-temperature and high-pressure gaseous carbon dioxide remaining inside the washing tub 11.

[0062] In detail, to recover gaseous carbon dioxide, a recovery channel 106 connecting the washing tub 11, the compressor 13, the distillation tank 14, and the cooler 15 is opened. The recovery channel 106 includes an intake recovery channel 1061 connecting the intake of the washing tub 11 and the compressor 13, an outlet recovery channel 1062 connecting the outlet of the compressor 13 and the washing tub 11 and the distillation tank 14, and a condensation recovery channel 1063 extending from the outlet recovery channel 1062 and reconnecting to the distillation tank 14 via the distillation tank 14 and the cooler 15.

[0063] If the recycling process begins, the gaseous carbon dioxide inside the washing tub 11 is discharged through the suction recycling channel 1061 and flows into the compressor 13. Furthermore, the carbon dioxide discharged through the suction recycling channel 1061 is compressed to high temperature and high pressure by the compressor 13 and then discharged into the discharge recycling channel 1062.

[0064] The aforementioned discharge recovery channel 1062 extends to the distillation tank 14 after passing through the interior of the washing tub 11. Therefore, the high-temperature, high-pressure gaseous carbon dioxide discharged from the compressor 13 passes through the interior of the washing tub 11 and only releases heat into the interior of the washing tub 11, without mixing with the gaseous carbon dioxide inside the washing tub 11. During this process, the temperature inside the washing tub 11 rises, preventing carbon dioxide from leaking out and causing a sharp drop in the temperature inside the washing tub 11. As a result, it prevents the phenomenon where, at the time of removing the laundry after washing, the temperature inside the washing tub is significantly lower than the external temperature, thus preventing moisture condensation on the surface of the laundry when it is removed.

[0065] The carbon dioxide, whose temperature drops as it passes through the washing tub 11, exchanges heat with the liquid carbon dioxide inside the distillation tank 14 as it passes through the distillation tank 14, thereby further reducing its temperature and pressure. A portion of the liquid carbon dioxide inside the distillation tank 14 is vaporized.

[0066] Furthermore, the carbon dioxide cooled in the distillation tank 14 is condensed into liquid carbon dioxide in the cooler 15 and then flows back into the distillation tank 14. During the recovery process, the amount of gaseous carbon dioxide inside the washing tank 11 decreases, while the pressure inside the washing tank 11 gradually decreases, and the water level of the liquid carbon dioxide recovered to the distillation tank 14 gradually rises.

[0067] Furthermore, the recycling process ends when the pressure inside the washing tub 11 drops to a set pressure. The pressure inside the washing tub 11 used to determine whether to end the recycling process can be approximately 2.5 bar, but is not limited to this. The set pressure is determined based on the allowable compression ratio of the compressor 13. This compression ratio can be defined as discharge pressure / intake pressure. If the compressor 13 operates beyond the allowable compression ratio, it exceeds the reliability tolerance of the compressor 13, potentially leading to compressor damage or performance degradation.

[0068] For example, in a compressor with a permissible compression ratio of 15, if the discharge pressure is 38 bar, the intake pressure cannot be reduced to less than 2.5 bar. The intake pressure is equivalent to the pressure inside the washing tub 11, and the discharge pressure is equivalent to the pressure inside the storage tank 12. Therefore, during the recycling process, when the pressure inside the washing tub 11 reaches 2.5 bar, further recycling cannot proceed. In this state, the recycling process ends, and the small amount of gaseous carbon dioxide remaining inside the washing tub 11 is discarded to the outside through the exhaust channel 101.

[0069] Furthermore, through the exhaust process, the internal pressure of the washing tub 11 becomes the same as the atmospheric pressure, thus ending the entire washing process and allowing the washing tub 11 door to be opened to remove the items to be washed.

[0070] The multiple flow channels described above can be formed as separate and independent flow channels. To simplify the pipe configuration, they can also share at least a portion or all of the flow channels with other flow channels. For example, the compressor suction flow channel 1031 constituting the liquid phase supply flow channel 103 is the same flow channel as the suction-side passage flow channel 1051 constituting the passage flow channel 105, but they can be defined as different flow channel names depending on which process the carbon dioxide flows in. Undoubtedly, the liquid phase supply flow channel 103 and the suction-side passage flow channel 1051 can also be formed as separate and independent flow channels.

[0071] On the other hand, if a power outage or malfunction of any component of the washing machine 10 occurs during the washing or rinsing process described above, the washing process should be stopped immediately. In this state, a reset procedure according to the present invention should be performed immediately, the details of which are described below with reference to the flowchart.

[0072] Figure 9 This is a flowchart illustrating the reset process of a washing machine according to an embodiment of the present invention.

[0073] Reference Figure 9 If a power outage or malfunction occurs at a certain point after the washing process has started, the washing machine will stop running and generate a warning signal. Furthermore, the reset process according to the present invention will be immediately initiated at the point when the power outage is resolved and power is restored, or at the point when the warning signal caused by the malfunction occurs.

[0074] During the above reset process, the control unit of the washing machine 10 determines whether the internal pressure of the washing tub 11 is above a first set pressure (S11). The first set pressure is the minimum suction pressure that satisfies the allowable compression ratio of the compressor 11, specifically representing the internal pressure of the washing tub 11. For example, it can be 2.5 bar, but the set pressure value may be different depending on the type of compressor 13.

[0075] Specifically, when it is determined that the pressure in the washing tub 11 is above the first set pressure, the process is first carried out in... Figure 5 The liquid phase carbon dioxide removal process described in section (S12) ends after the liquid phase carbon dioxide removal is completed (S13), and then proceeds to... Figure 8 The gas phase carbon dioxide recovery process described in Section (S14) is as follows.

[0076] The time point at which the discharge of liquid carbon dioxide ends can be determined by various methods. For example, it can be determined as the time point at which the increase in the water level inside the distillation tank 14 stops, the time point at which the change in the pressure inside the distillation tank 14 stops, the time point at which a set time has elapsed since the discharge of liquid carbon dioxide, or the time point at which the rotation of the flow meter (not shown) installed in the liquid discharge channel 104 stops. Undoubtedly, various other methods can also be used.

[0077] Furthermore, during the recovery of gaseous carbon dioxide, when the pressure in the washing tub drops below the first set pressure, a gaseous carbon dioxide venting process (S15) is performed through the exhaust channel 101. This venting process continues until the pressure in the washing tub 11 drops to the second set pressure (S16). The second set pressure can represent atmospheric pressure.

[0078] On the other hand, at the time point of the reset process, if it is determined that the pressure of the washing tub 11 is less than the first set pressure, the carbon dioxide exhaust process (S15) is directly performed without the recovery process. When the pressure of the washing tub 11 is less than the first set pressure, there is no liquid carbon dioxide inside the washing tub 11, so a separate liquid carbon dioxide exhaust process is not required.

[0079] In this way, when the reset process is initiated and it is determined that the pressure in the washing tub is higher than the first set pressure, carbon dioxide is not immediately discharged. Instead, the recovery process continues until the pressure drops to the first set pressure, thus minimizing unnecessary carbon dioxide consumption.

[0080] Figure 10 This is a system diagram illustrating a method for recovering gaseous carbon dioxide according to another embodiment of the present invention.

[0081] Reference Figure 10 At the end Figure 9 After the liquid carbon dioxide is discharged in the control method described herein, the process of liquefying the gaseous carbon dioxide and recovering it to the distillation tank can be further carried out until the pressure inside the washing tub drops to the first set pressure, thereby storing the gaseous carbon dioxide in a separate storage tank 16 instead of discharging it immediately.

[0082] Specifically, the gaseous carbon dioxide is recovered and liquefied and then returned to the distillation tank 14 until the pressure inside the washing tub drops to the first set pressure. Furthermore, when the pressure inside the washing tub reaches the first set pressure, the gaseous carbon dioxide remaining inside the washing tub 11 is recovered to a separate storage tank 16.

[0083] As an example, the flow channel directly connecting the washing tub 11 and the separate storage tank 16 is opened so that the gaseous carbon dioxide remaining inside the washing tub 11 is recovered to the storage tank 16 through the pressure difference. The flow channel directly connecting the washing tub 11 and the storage tank 16 can be defined as a "natural recovery flow channel".

[0084] As a result, further reducing the amount of gaseous carbon dioxide released into the atmosphere can further reduce carbon dioxide consumption.

[0085] Figure 11 This is a flowchart illustrating the reset process of a washing machine according to another embodiment of the present invention.

[0086] Reference Figure 10 as well as Figure 11 When a problem occurs in the washing machine or a power outage triggers a reset process, it will perform a process similar to... Figure 9 The same steps (S21 to S24) are performed in steps S11 to S14. That is, when the pressure of the washing tub is above the first set pressure that satisfies the compression ratio of the compressor 13, the liquid phase carbon dioxide is discharged sequentially, the gaseous phase carbon dioxide inside the washing tub is liquefied and recovered to the distillation tank 14.

[0087] Furthermore, when the pressure in the washing tub reaches the first set pressure, the gaseous carbon dioxide is no longer released into the atmosphere. Instead, the gaseous carbon dioxide is naturally recovered into the washing tub 11 via the natural recovery channel 107 through the pressure difference (S25).

[0088] Furthermore, during the natural recovery of gaseous carbon dioxide to the storage tank 16, it is determined whether the pressure of the washing tub has changed (S16). If it is determined that the current sensing pressure of the washing tub is lower than the previous sensing pressure, the natural recovery process continues. If it is determined that the current sensing pressure is the same as the previous sensing pressure, it is determined whether the pressure of the washing tub is higher than the second set pressure, and as an example, it is determined whether it is higher than atmospheric pressure (S27).

[0089] The fact that the internal pressure of the washing tub remains unchanged means that the washing tub 11 and the storage tank 16 have achieved pressure equalization, and the gaseous carbon dioxide no longer moves. Therefore, when the pressure in the washing tub is higher than atmospheric pressure, the carbon dioxide remaining inside the washing tub is discharged into the atmosphere by the aforementioned vacuum pump 19 (S28).

[0090] Conversely, when it is determined that the constant washing tub pressure is not higher than atmospheric pressure, it is determined whether the sensed pressure is the same as atmospheric pressure (S29). Furthermore, if it is determined that the sensed pressure is the same as atmospheric pressure, the user can open the washing tub door, so the reset process ends.

[0091] Conversely, if it is determined that the pressure inside the washing tub is lower than atmospheric pressure, the vent hole 111 located on one side of the washing tub 11 is opened (S30) to make the pressure inside the washing tub the same as atmospheric pressure, after which the reset process can be ended. The aforementioned vent hole 111 can be automatically opened or closed by a solenoid valve or the like, or it can be manually opened or closed by the user.

[0092] On the other hand, the process of recovering gaseous carbon dioxide to the distillation tank 14 is defined as the first recovery process, and the process of recovering gaseous carbon dioxide to the storage tank 16 is defined as the second recovery process.

[0093] Figure 12 This is a system diagram illustrating a method for recovering gaseous carbon dioxide according to yet another embodiment of the present invention.

[0094] Reference Figure 12 , such as in Figure 10 as well as Figure 11 The description indicates that the system diagram according to this embodiment is characterized by having a separate storage tank 16 for recovering gaseous carbon dioxide. However, the difference lies in that, compared to... Figure 10 Unlike the natural recovery method described above, the above-mentioned compressor 13 is used to forcibly recover gaseous carbon dioxide.

[0095] In detail, through the recycling channel, the so-called "forced recycling channel" connecting the washing tub 11, the compressor 13, and the storage tank 16, the gaseous carbon dioxide inside the washing tub 11 can be recycled to the storage tank 16.

[0096] The forced recovery process of gaseous carbon dioxide using the compressor 13 described above can be performed in... Figure 10 as well as Figure 11 The process described above can occur immediately after the natural recycling process, or it can be separated from the natural recycling process. This feature is further explained in detail below with reference to the flowchart.

[0097] Figure 13 This is a flowchart illustrating the reset process of a washing machine according to another embodiment of the present invention.

[0098] Reference Figure 12 as well as Figure 13 ,like Figure 9 as well as Figure 11The description states that when the reset process start conditions are met, the control unit of the washing machine 10 sequentially performs the step of determining whether the internal pressure of the washing tub 11 is above the first set pressure to carry out the gas phase carbon dioxide recovery step (S31~S34).

[0099] Furthermore, when it is determined that the pressure in the washing tub 11 is not higher than the first set pressure, the compressor 13 starts operating, and the gaseous carbon dioxide inside the washing tub 11 is forcibly recovered to the storage tank 16 along the forced recovery channel 108 (S35). The forced recovery process continues until the pressure in the washing tub drops to atmospheric pressure, which is the second set pressure (S36). When the pressure in the washing tub reaches atmospheric pressure, the user can directly open the washing tub door, so the reset process ends.

[0100] Figure 14 This is a flowchart illustrating the reset process of a washing machine according to another embodiment of the present invention.

[0101] Reference Figure 14 ,and Figure 9 , Figure 11 as well as Figure 13 Similar to the method described above, according to the reset process of the washing machine in this embodiment, when the reset process start condition is met, the step of the control unit of the washing machine 10 determining whether the internal pressure of the washing tub 11 is above the first set pressure is performed in sequence to carry out the gas phase carbon dioxide recovery step (S41~S44).

[0102] Furthermore, when it is determined that the pressure in the aforementioned washing tub 11 is not higher than the first set pressure, such as in Figure 11 The description states that a second recovery process is performed to recover the gaseous carbon dioxide inside the washing tub 11 to the storage tank 16.

[0103] It should be noted that, with Figure 11 or Figure 13 The difference in the second recycling process described above is that the natural recycling process and the forced recycling process are carried out sequentially in the second recycling process.

[0104] In detail, during the first recycling process described above, if it is determined that the pressure of the washing tub 11 is not higher than the first set pressure, a natural recycling process (S45) is first carried out to recover gaseous carbon dioxide to the storage tank 16 via the natural recycling channel 107.

[0105] Furthermore, during the aforementioned natural recycling process, it is determined whether there is a change in the pressure inside the washing tub (S46). If it is determined that the current sensed pressure inside the washing tub is lower than the previous sensed pressure, the aforementioned natural recycling process continues. Conversely, if it is determined that the current sensed pressure is the same as the previous sensed pressure, it indicates that carbon dioxide is no longer moving from the washing tub 11 to the storage tank 16, and therefore the aforementioned natural recycling process ends.

[0106] Furthermore, it is determined whether the internal pressure of the washing tub, which is maintained at a constant value, is higher than the atmospheric pressure, which is the second set pressure (S47). If it is determined that the pressure of the washing tub is higher than the atmospheric pressure, a process of forced recovery of gaseous carbon dioxide is performed (S48). That is, the compressor 13 starts to run, the forced recovery channel 108 is opened, and the gaseous carbon dioxide remaining inside the washing tub 11 is forcibly recovered to the storage tank 16.

[0107] Furthermore, if it is determined that the pressure in the washing tub during the forced recovery process reaches atmospheric pressure, indicating that the user can open the washing tub door, the reset process is terminated. At this time, the gaseous carbon dioxide remaining inside the washing tub 11 is discharged into the atmosphere through the opening of the washing tub door.

[0108] On the other hand, if it is determined that the internal pressure of the aforementioned washing tub, which is maintained at a constant level, is the same as the atmospheric pressure, then the user is able to open the door of the aforementioned washing tub, and the aforementioned reset process ends.

[0109] Conversely, if it is determined that the internal pressure of the aforementioned washing tub, which is maintained at a constant level, is lower than atmospheric pressure, the user is unable to open the door of the washing tub. In this case, the vent 111 is opened (S51) to bring the internal pressure of the washing tub to the same level as atmospheric pressure, and then the reset process ends.

Claims

1. A control method for a washing machine, wherein the washing machine uses carbon dioxide as a washing solvent, and the washing machine comprises: A laundry tub for holding laundry; a compressor for compressing gaseous carbon dioxide; A distillation tank in which liquid carbon dioxide and gaseous carbon dioxide coexist; and a washing flow channel connecting the washing tub, the compressor, and the distillation tank, in the control method of the washing machine, When an abnormal situation occurs and the washing machine stops operating, a reset process to expel carbon dioxide from inside the washing tub is initiated. The above reset process includes: The step of sensing the pressure inside the washing tub described above; The step of determining that the pressure inside the washing tub is higher than the first set pressure, thereby discharging liquid carbon dioxide; and After the discharge of liquid carbon dioxide is completed, the gaseous carbon dioxide inside the washing tank is recovered to the distillation tank until the pressure inside the washing tank reaches the first set pressure.

2. The control method for a washing machine according to claim 1, characterized in that, The aforementioned abnormal conditions include at least one of the following: a power outage or a malfunction of the washing machine. The reset process should be performed at the point when power is restored after a power outage or at the point when an alarm signal indicating a malfunction in the washing machine is issued.

3. The control method for a washing machine according to claim 1, characterized in that, The first set pressure mentioned above is the minimum suction pressure that satisfies the allowable compression ratio of the compressor.

4. The control method for a washing machine according to claim 3, characterized in that, The minimum inhalation pressure mentioned above is 2.5 bar.

5. The control method for a washing machine according to claim 3, characterized in that, During the period when the gaseous carbon dioxide inside the washing tub is recovered to the distillation tank, when the internal pressure of the washing tub drops to the first set pressure, the gaseous carbon dioxide recovery process ends, and the gaseous carbon dioxide remaining inside the washing tub is released into the atmosphere.

6. The control method for a washing machine according to claim 5, characterized in that, When the internal pressure of the washing tub reaches the second preset pressure, the reset process ends. The second set pressure is lower than the first set pressure.

7. The control method for a washing machine according to claim 6, characterized in that, When it is determined that the pressure inside the washing tub sensed after the above reset process has just been initiated is not higher than the first set pressure, the process of directly releasing the gaseous carbon dioxide remaining inside the washing tub into the atmosphere is carried out. When the internal pressure of the washing tub reaches the second set pressure, the reset process ends.

8. The control method for a washing machine according to claim 3, characterized in that, During the period when the gaseous carbon dioxide inside the washing tub is recovered to the distillation tank, when the internal pressure of the washing tub drops to the first set pressure, the gaseous carbon dioxide remaining inside the washing tub is naturally recovered to the storage tank through the natural recovery channel connecting the washing tub and the storage tank.

9. The control method for a washing machine according to claim 8, characterized in that, The above-mentioned natural recycling process continues until the internal pressure of the washing tub remains constant.

10. The control method for a washing machine according to claim 9, characterized in that, When the internal pressure of the aforementioned constant washing tub exceeds the second set pressure, gaseous carbon dioxide inside the washing tub is released into the atmosphere. When the internal pressure of the washing tub reaches the second preset pressure, the reset process ends. The second set pressure is lower than the first set pressure.

11. The control method for a washing machine according to claim 9, characterized in that, When the internal pressure of the aforementioned constant washing tub is lower than the second set pressure, the vent located on one side of the washing tub is opened. When the internal pressure of the washing tub reaches the second preset pressure, the reset process ends. The second set pressure is lower than the first set pressure.

12. The control method for a washing machine according to claim 9, characterized in that, When the internal pressure of the aforementioned constant washing tub is higher than the second set pressure, the gaseous carbon dioxide inside the washing tub is forcibly recovered to the storage tank through the forced recovery flow channel connecting the washing tub, the compressor, and the storage tank. The second set pressure is lower than the first set pressure.

13. The control method for a washing machine according to claim 12, characterized in that, The forced recovery process continues until the pressure inside the washing tub reaches the second set pressure, and then the reset process ends.

14. The control method for a washing machine according to claim 3, characterized in that, During the period when the gaseous carbon dioxide inside the washing tub is recovered to the distillation tank, when the internal pressure of the washing tub drops to the first set pressure, the gaseous carbon dioxide inside the washing tub is forcibly recovered to the storage tank through the forced recovery channel connecting the washing tub, the compressor and the storage tank.

15. The control method for a washing machine according to claim 14, characterized in that, The forced recovery process continues until the pressure inside the washing tub reaches the second preset pressure, and then the reset process ends. The second set pressure is lower than the first set pressure.

16. The control method for a washing machine according to any one of claims 6, 10 to 12 and 15, characterized in that, The second set pressure mentioned above is atmospheric pressure.

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