Washing machine

Abstract

This washing machine comprises: a washing tub for washing laundry by using carbon dioxide; a first storage tank and a second storage tank for storing carbon dioxide; a first flow path for connecting a compressor and the first storage tank; a second flow path for connecting the compressor and the second storage tank; a first valve for opening and closing the first flow path; a second valve for opening and closing the second flow path; and a control unit for controlling the compressor, the first valve and the second valve. The control unit operates the compressor so as to compress the carbon dioxide recovered from the washing tub when washing is complete, opens the first valve so that the compressed carbon dioxide moves from the compressor to the first storage tank along the first flow path, and closes the first valve and opens the second valve so that the compressed carbon dioxide moves from the compressor to the second storage tank along the second flow path on the basis of the pressure inside the washing tub.

Description

washing machine

[0001] The present disclosure relates to a washing machine.

[0002] Typically, washing machines are devices that use water as a detergent. Conversely, there are dry cleaning washing machines that use detergents, which are volatile organic compounds, instead of water to clean laundry without using water. Dry cleaning washing machines can use solvents, such as solvents or petroleum-based detergents.

[0003] Washing machines that use water pollute the environment by generating wastewater during the washing process, and solvent-based and petroleum-based cleaning solvents used in dry cleaning machines are harmful to the human body and can pollute the environment.

[0004] Carbon dioxide can be used as a replacement for the aforementioned cleaning solvents. Carbon dioxide has a lower viscosity than water, allowing it to easily penetrate fibers and remove contaminants. After washing, the carbon dioxide containing foreign substances can be vaporized to separate the carbon dioxide and the contaminants, and the vaporized carbon dioxide can be reused.

[0005] Carbon dioxide is a component of the general atmosphere, so it does not pollute the environment, and since liquid carbon dioxide is vaporized and liquefied and reused, carbon dioxide emissions are low, so it can also contribute to achieving carbon neutrality.

[0006] One aspect of the present disclosure provides a washing machine capable of depressurizing the inside of a washing tub using only one compressor after a washing cycle by including two carbon dioxide storage tanks having different internal pressures.

[0007] One aspect of the present disclosure provides a washing machine capable of preventing overload of a compressor by recovering carbon dioxide inside a washing tank by dividing it into a first storage tank and a second storage tank.

[0008] The technical problems to be achieved in this document are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0009] According to one embodiment, a washing machine includes a washing tub configured to wash laundry using carbon dioxide, a compressor connected to the washing tub and configured to compress carbon dioxide, a first storage tank configured to store carbon dioxide, a second storage tank configured to store carbon dioxide, a first flow path connecting the compressor and the first storage tank, a second flow path connecting the compressor and the second storage tank, a first valve configured to open and close the first flow path, a second valve configured to open and close the second flow path, the compressor, and a control unit configured to control the first valve and the second valve. The control unit operates the compressor to compress carbon dioxide recovered from the washing tub when washing is completed, opens the first valve so that the compressed carbon dioxide moves from the compressor to the first storage tank along the first flow path, and closes the first valve and opens the second valve so that the compressed carbon dioxide moves from the compressor to the second storage tank along the second flow path based on the pressure inside the washing tub.

[0010] According to one embodiment, a control method for a washing machine including a first storage tank, a second storage tank different from the first storage tank, and a washing tub includes the steps of supplying carbon dioxide from the first storage tank and the second storage tank to the washing tub to wash laundry, and, after washing is completed, depressurizing the inside of the washing tub to open the washing tub and recovering carbon dioxide inside the washing tub. The step of recovering carbon dioxide inside the washing tub includes the steps of moving carbon dioxide inside the washing tub to the first storage tank, and the steps of moving carbon dioxide inside the washing tub to the second storage tank.

[0011] FIG. 1 is a conceptual diagram illustrating a carbon dioxide flow in a washing machine according to one embodiment of the present disclosure.

[0012] FIG. 2 is a control block diagram of a washing machine according to one embodiment of the present disclosure.

[0013] FIG. 3 is a conceptual diagram illustrating a path of gaseous carbon dioxide moving from a second storage tank to a washing tub in a washing machine according to one embodiment of the present disclosure.

[0014] FIG. 4 is a conceptual diagram illustrating a path of carbon dioxide moving from a first storage tank to a washing tub in a washing machine according to one embodiment of the present disclosure.

[0015] FIG. 5 is a conceptual diagram illustrating a path of carbon dioxide moving from a replenishment tank to a washing tub in a washing machine according to one embodiment of the present disclosure.

[0016] FIG. 6 is a conceptual diagram illustrating a flow path of liquid carbon dioxide moving from a first storage tank to a washing tub in a washing machine according to one embodiment of the present disclosure.

[0017] FIG. 7 is a conceptual diagram illustrating a path of gaseous carbon dioxide moving from a washing tank to a distillation tank and a path of liquid carbon dioxide moving from a washing tank to a distillation tank in a washing machine according to one embodiment of the present disclosure.

[0018] FIG. 8 is a conceptual diagram illustrating a process of recovering carbon dioxide inside a distillation tank to a first storage tank in a washing machine according to one embodiment of the present disclosure.

[0019] FIG. 9 is a conceptual diagram illustrating a process of recovering carbon dioxide inside a washing machine tub into a first storage tank according to one embodiment of the present disclosure.

[0020] FIG. 10 is a conceptual diagram illustrating a process of recovering carbon dioxide inside a washing machine tub to a second storage tank according to one embodiment of the present disclosure.

[0021] It should be understood that the various embodiments and terms used in this document are not intended to limit the technical features described in this document to specific embodiments, but rather to include various modifications, equivalents, or substitutes of the embodiments.

[0022] In connection with the description of the drawings, similar reference numerals may be used for similar or related components.

[0023] The singular form of a noun corresponding to an item may include one or more of said items, unless the relevant context clearly indicates otherwise.

[0024] In this document, each of the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" may include any one of the items listed together in that phrase, or all possible combinations thereof.

[0025] The term "and / or" includes any combination of a plurality of related described elements or any one of a plurality of related described elements.

[0026] Terms such as "first," "second," or "first" or "second" may be used simply to distinguish one component from another and do not qualify the components in any other respect (e.g., importance or order).

[0027] When a component (e.g., a first component) is referred to as being "coupled" or "connected" to another component (e.g., a second component), with or without the terms "functionally" or "communicatively," it means that the component can be connected to the other component directly (e.g., wired), wirelessly, or through a third component.

[0028] The terms "include" or "have" are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in this document, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0029] When a component is said to be “connected,” “coupled,” “supported,” or “in contact with” another component, this includes not only cases where the components are directly connected, coupled, supported, or in contact, but also cases where the components are indirectly connected, coupled, supported, or in contact through a third component.

[0030] When we say that a component is "on" another component, this includes not only cases where the component is in contact with the other component, but also cases where there is another component between the two components.

[0031] Washing machines according to various embodiments may include a housing that accommodates various components therein. The housing may be provided in the form of a box with a laundry inlet formed on one side.

[0032] A washing machine may include a door for opening and closing the laundry compartment. The door may be rotatably mounted to the housing by a hinge. At least a portion of the door may be transparent or translucent to allow the interior of the housing to be viewed.

[0033] A washing machine may include a drum configured to accommodate laundry.

[0034] The drum can rotate within the housing and perform each operation according to the washing and rinsing cycles. A plurality of holes can be formed in the cylindrical wall of the drum.

[0035] A washing machine may include a drive device configured to rotate a drum. The drive device may include a drive motor and a rotating shaft for transmitting driving force generated by the drive motor to the drum.

[0036] The driving device can perform each operation according to the washing and rinsing cycle by rotating the drum forward or backward.

[0037] The washing machine may include a control panel positioned on one side of the housing. The control panel may provide a user interface for a user to interact with the washing machine. The user interface may include at least one input interface and at least one output interface.

[0038] At least one input interface can convert sensory information received from a user into an electrical signal.

[0039] At least one input interface may include a power button, an operation button, a course selection dial (or course selection button), and a wash / rinse button. The at least one input interface may include, for example, a tact switch, a push switch, a slide switch, a toggle switch, a micro switch, a touch switch, a touch pad, a touch screen, a jog dial, and / or a microphone.

[0040] At least one output interface can visually or audibly convey information related to the operation of the washing machine to the user.

[0041] For example, at least one output interface may transmit information related to the washing cycle, operating time of the washing machine, and washing / rinsing settings to the user. Information related to the operation of the washing machine may be output via a screen, indicator, voice, etc. The at least one output interface may include, for example, a liquid crystal display (LCD) panel, a light emitting diode (LED) panel, a speaker, etc.

[0042] The washing machine may include a communication module for communicating with external devices via wires and / or wirelessly.

[0043] The communication module may include at least one of a short-range communication module or a long-range communication module.

[0044] The communication module can transmit data to or receive data from external devices (e.g., a server, a user device, and / or a home appliance). For example, the communication module can establish communication with a server, a user device, and / or a home appliance, and transmit and receive various data.

[0045] To this end, the communication module may support the establishment of a direct (e.g., wired) communication channel or a wireless communication channel between external devices, and the performance of communication through the established communication channel. According to one embodiment, the communication module may include a wireless communication module (e.g., a cellular communication module, a short-range wireless communication module, or a global navigation satellite system (GNSS) communication module) or a wired communication module (e.g., a local area network (LAN) communication module, or a power line communication module). Any of these communication modules may communicate with the external device via a first network (e.g., a short-range communication network such as Bluetooth, wireless fidelity (WiFi) direct, or infrared data association (IrDA)) or a second network (e.g., a long-range communication network such as a legacy cellular network, a 5G network, a next-generation communication network, the Internet, or a computer network (e.g., a LAN or WAN)). These various types of communication modules may be integrated into a single component (e.g., a single chip) or implemented as multiple separate components (e.g., multiple chips).

[0046] The short-range wireless communication module may include, but is not limited to, a Bluetooth communication module, a BLE (Bluetooth Low Energy) communication module, a near field communication module, a WLAN (Wi-Fi) communication module, a Zigbee communication module, an infrared (IrDA, infrared Data Association) communication module, a WFD (Wi-Fi Direct) communication module, an UWB (ultrawideband) communication module, an Ant+ communication module, a microwave (uWave) communication module, etc.

[0047] The remote communication module may include a communication module that performs various types of remote communication and may include a mobile communication unit. The mobile communication unit transmits and receives wireless signals with at least one of a base station, an external terminal, and a server on a mobile communication network.

[0048] In one embodiment, the communication module can communicate with external devices such as a server, a user device, and other home appliances through a peripheral access point (AP). The access point (AP) can connect a local area network (LAN) to which the washing machine or the user device is connected to a wide area network (WAN) to which the server is connected. The washing machine or the user device can be connected to the server through the wide area network (WAN). The control unit can control various components of the washing machine, such as a drive motor. The control unit can control various components of the washing machine to perform at least one cycle, including water supply, washing, and rinsing, based on user input. For example, the control unit can control the drive motor to adjust the rotation speed of the drum.

[0049] The control unit may include hardware such as a CPU or memory, and software such as a control program. For example, the control unit may include an algorithm for controlling the operation of components within the washing machine, at least one memory storing program-type data, and at least one processor performing the aforementioned operation using data stored in the at least one memory. The memory and the processor may each be implemented as separate chips. The processor may include one or more processor chips or one or more processing cores. The memory may include one or more memory chips or one or more memory blocks. Additionally, the memory and the processor may be implemented as a single chip.

[0050] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the attached drawings.

[0051] Figure 1 is a conceptual diagram illustrating the carbon dioxide flow of a washing machine according to one embodiment.

[0052] Referring to FIG. 1, a washing machine according to one embodiment may include a first storage tank (10) and a second storage tank (40) configured to store carbon dioxide, a washing tub (20) that performs laundry internally using carbon dioxide, a distillation tank (30) configured to receive carbon dioxide and foreign substances discharged from the washing tub (20), a foreign substance tank (70) configured to store and discharge foreign substances discharged from the distillation tank (30), a compressor (50) configured to compress carbon dioxide, and a chiller (11) configured to cool the first storage tank (10). The washing machine may further include a replenishment tank (60) configured to replenish carbon dioxide lost in the process of recovering carbon dioxide after washing.

[0053] The first storage tank (10) may be configured to store carbon dioxide. The first storage tank (10) may be configured to store gaseous carbon dioxide and liquid carbon dioxide. The first storage tank (10) may maintain an internal pressure above a predetermined pressure so as to store liquid carbon dioxide. The first storage tank (10) may store carbon dioxide at a first pressure level. For example, the first pressure level may be approximately 30 to 70 bar. In other words, the internal pressure of the first storage tank (10) may be approximately 30 to 70 bar.

[0054] The first storage tank (10) may include a first outlet designed to mainly discharge gaseous carbon dioxide and a second outlet designed to mainly discharge liquid carbon dioxide. The first storage tank (10) may include an inlet through which carbon dioxide is introduced from the outside. The first outlet may be formed at a higher position than the second outlet so that liquid carbon dioxide inside the first storage tank (10) is not discharged through the first outlet, but gaseous carbon dioxide is mainly discharged. The inlet may be formed at a higher position than the second outlet so that liquid carbon dioxide inside the first storage tank (10) is not discharged through the inlet. For example, the first outlet and the inlet may be formed at a position higher than the full water level of the liquid carbon dioxide stored in the first storage tank (10). However, liquid carbon dioxide and gaseous carbon dioxide coexist inside the first storage tank (10), and depending on temperature and pressure conditions, the liquid carbon dioxide may be vaporized into gaseous carbon dioxide or the gaseous carbon dioxide may be liquefied into liquid carbon dioxide. Accordingly, gaseous carbon dioxide and liquid carbon dioxide can be discharged together through the first outlet, liquid carbon dioxide and gaseous carbon dioxide can be discharged together through the second outlet, and gaseous carbon dioxide and liquid carbon dioxide can be introduced together or liquid carbon dioxide can be introduced through the inlet.

[0055] The chiller (11) may be provided to cool the first storage tank (10). The chiller (11) may liquefy gaseous carbon dioxide inside the first storage tank (10) by cooling the first storage tank (10). Through this, gaseous carbon dioxide recovered from the washing tank (20) and the distillation tank (30) may be liquefied. The liquefied carbon dioxide may be discharged back to the washing tank (20) from the first storage tank (10) and used for washing. The chiller (11) may liquefy carbon dioxide recovered in a gaseous state, thereby allowing the carbon dioxide to circulate through the first storage tank (10), the washing tank (20), and the distillation tank (30). The chiller (11) may include an evaporator of a heat pump. Alternatively, the chiller (11) may include at least one of various types of cooling devices.

[0056] According to one embodiment, the chiller (11) can liquefy the gaseous carbon dioxide recovered from the distillation tank (30) or the washing tank (20) to the first storage tank (10) before it flows into the first storage tank (10). This allows liquid carbon dioxide to flow into the first storage tank (10) instead of gaseous carbon dioxide. Flowing liquid carbon dioxide into the first storage tank (10) may be more advantageous in terms of stability than flowing gaseous carbon dioxide. Alternatively, a cooling device other than the chiller (11) can liquefy the gaseous carbon dioxide recovered from the distillation tank (30) or the washing tank (20) to the first storage tank (10). The cooling device may include an evaporator of a heat pump.

[0057] The washing tub (20) can provide a space for washing laundry using liquid carbon dioxide as a washing solvent. The washing tub (20) can store liquid carbon dioxide and gaseous carbon dioxide inside. The washing tub (20) can maintain an internal pressure above a predetermined pressure so that the liquid carbon dioxide can be stored inside. The internal pressure of the washing tub (20) can be maintained at approximately 30 to 60 bar. A drum (not shown) can be rotatably arranged inside the washing tub (20).

[0058] The washing tank (20) may be positioned lower than the first storage tank (10). Accordingly, the carbon dioxide stored in the first storage tank (10) may be moved from the first storage tank (10) to the washing tank (20) by gravity without power. Mainly, the liquid carbon dioxide may be moved to the washing tank (20) through the second outlet of the first storage tank (10) by gravity.

[0059] During the process of loading laundry into the drum within the washing tub (20), air may be introduced into the washing tub (20). If air is introduced into the washing tub (20), moisture contained in the air may condense during the process of lowering the pressure within the washing tub (20) after the washing process is completed. If moisture introduced between the laundry condenses, the laundry may be damaged. To prevent this, the washing machine may include a vacuum pump (120) configured to exhaust air within the washing tub (20).

[0060] The distillation tank (30) may be provided to receive carbon dioxide and foreign substances discharged from the washing tank (20) after washing. Specifically, the distillation tank (30) may receive liquid carbon dioxide discharged from the washing tank (20), foreign substances dissolved or not dissolved in the liquid carbon dioxide, and gaseous carbon dioxide therein.

[0061] The washing machine can recover carbon dioxide inside the distillation tank (30) into the first storage tank (10). The gaseous carbon dioxide inside the distillation tank (30) can move to the input terminal of the compressor (50) by the pressure difference, and the carbon dioxide introduced into the input terminal of the compressor (50) can be compressed by the compressor (50) and then moved to the first storage tank (10). The liquid carbon dioxide inside the distillation tank (30) can be vaporized by the heat applied to the distillation tank (30). The vaporized gaseous carbon dioxide can move to the input terminal of the compressor (50), be compressed by the compressor (50), and then moved to the first storage tank (10), as described above. As the liquid carbon dioxide vaporizes, foreign substances dissolved in the liquid carbon dioxide can be separated from the liquid carbon dioxide. The foreign substances inside the distillation tank (30) can be discharged to the foreign substance tank (70) after the carbon dioxide inside the distillation tank (30) is recovered to the first storage tank (10).

[0062] In the above process, the gaseous carbon dioxide discharged from the distillation tank (30) becomes high-temperature and high-pressure gaseous carbon dioxide while passing through the compressor (50). The gaseous carbon dioxide, whose temperature has increased by passing through the compressor (50), can supply heat to the interior of the distillation tank (30) by exchanging heat with the distillation tank (30). In the process of recovering the carbon dioxide inside the distillation tank (30) to the first storage tank (10), the temperature of the carbon dioxide passing through the compressor (50) increases, and the heat of this carbon dioxide is supplied to the distillation tank (30), thereby vaporizing the liquid carbon dioxide inside the distillation tank (30). According to one embodiment, the high-temperature carbon dioxide passing through the compressor (50) exchanges heat with the carbon dioxide inside the distillation tank (30) while passing through the distillation tank (30), thereby supplying heat to the distillation tank (30) without including a separate heat source such as a heater. In order to supply more heat to the distillation tank (30), a heating device such as a heater may be additionally included.

[0063] According to one embodiment, the gaseous carbon dioxide recovered from the distillation tank (30) to the first storage tank (10) may be liquefied by heat exchange with a chiller (11) or a separate heat exchanger before being introduced into the first storage tank (10) and may be introduced into the first storage tank (10) as liquid carbon dioxide. In other words, the carbon dioxide recovered from the distillation tank (30) to the first storage tank (10) may be introduced into the first storage tank (10) in a liquid state. To this end, the gaseous carbon dioxide recovered from the distillation tank (30) may be liquefied by a chiller (11) before being introduced into the first storage tank (10) or may be liquefied by being cooled by a separate heat exchanger not shown in the drawing. It may be advantageous in terms of safety to liquefy the gaseous carbon dioxide and then introduce the liquid carbon dioxide rather than to directly introduce the gaseous carbon dioxide into the first storage tank (10).

[0064] A foreign matter tank (70) may be provided to store foreign matter discharged from the distillation tank (30). A user may discharge the foreign matter stored in the foreign matter tank (70) at an appropriate interval. The emptying interval of the foreign matter tank (70) may vary depending on the capacity of the foreign matter tank (70) and the amount of foreign matter contained in the laundry.

[0065] The second storage tank (40) may be configured to store carbon dioxide. The second storage tank (40) may be configured to store carbon dioxide internally. The second storage tank (40) may primarily store gaseous carbon dioxide internally. The second storage tank (40) may store carbon dioxide at a second pressure level. The second pressure level may be approximately 10 to 70 bar. In other words, the internal pressure of the second storage tank (40) may be approximately 10 to 70 bar.

[0066] According to one embodiment, the second storage tank (40) can store carbon dioxide at a lower pressure level than the first storage tank (10). Since the first storage tank (10) can store carbon dioxide therein at approximately 30 to 70 bar, and the second storage tank (40) can store carbon dioxide therein at approximately 10 to 70 bar, the carbon dioxide storage pressure of the second storage tank (40) can be lower than the carbon dioxide storage pressure of the first storage tank (10). As described below, in the process of pressurizing the washing tub (20), when the carbon dioxide of the second storage tank (40) is supplied first and the carbon dioxide of the first storage tank (10) is supplied later, it is preferable that the internal pressure of the second storage tank (40) be lower than the internal pressure of the first storage tank (10). However, it is not limited to this, and the internal pressure of the second storage tank (40) may be set to be equal to or greater than the internal pressure of the first storage tank (10).

[0067] The supplementary tank (60) may be provided to supplement carbon dioxide lost in the process of recovering carbon dioxide after washing. The supplementary tank (60) may be provided to store carbon dioxide therein. The supplementary tank (60) may supply carbon dioxide to the washing tub (20). The supplementary tank (60) may be provided to be detachable from the washing machine. The supplementary tank (60) may be provided to be replaceable with another supplementary tank. Alternatively, the supplementary tank (60) may be provided to be detachable from the washing machine, replenish carbon dioxide therein, and then reattachable to the washing machine. The pressure inside the supplementary tank (60) may be provided to be equal to or higher than the pressure inside the first storage tank (10). The pressure inside the supplementary tank (60) may be provided to be equal to or higher than the pressure inside the second storage tank (40). The pressure inside the supplementary tank (60) may be provided to be higher than the pressure inside the washing tub (20).

[0068] Referring to Fig. 1, the washing machine may include a valve provided on a path through which carbon dioxide moves. The path may include a gas path through which gaseous carbon dioxide primarily moves and a liquid path through which liquid carbon dioxide primarily moves. The valve may include a gas valve provided to open and close the gas path through which gaseous carbon dioxide primarily moves. The valve may include a liquid valve provided to open and close the liquid path through which liquid carbon dioxide primarily moves. The washing machine may include a path connection through which a plurality of paths are combined into a single path or a single path is branched into a plurality of paths.

[0069] Specifically, the valve may include a first valve to an eighteenth valve (101 to 118). The euro may include a first euro to a twelfth euro (201 to 212). The euro connection may include a first euro connection to a sixth euro connection (301 to 306).

[0070] Figure 2 is a control block diagram of a washing machine according to one embodiment.

[0071] Referring to FIG. 2, the washing machine may include a first pressure sensor (81) configured to measure the pressure inside the first storage tank (10), a second pressure sensor (82) configured to measure the pressure inside the washing tub (20), and a third pressure sensor (83) configured to measure the pressure inside the second storage tank (40).

[0072] The washing machine may include a control unit (80) configured to control the first to eighteenth valves (101 to 118), a compressor (50), and a vacuum pump (120).

[0073] The control unit (80) can receive pressure data measured by the first pressure sensor (81), the second pressure sensor (82), and the third pressure sensor (83), respectively. The control unit (80) can control the first to eighteenth valves (101 to 118), the compressor (50), and the vacuum pump (120) based on the pressure data received from the first pressure sensor (81), the second pressure sensor (82), and the third pressure sensor (83).

[0074] FIG. 3 is a conceptual diagram illustrating a path of carbon dioxide gas moving from a second storage tank to a washing tub in a washing machine according to one embodiment. FIG. 4 is a conceptual diagram illustrating a path of carbon dioxide gas moving from a first storage tank to a washing tub in a washing machine according to one embodiment. FIG. 5 is a conceptual diagram illustrating a path of carbon dioxide gas moving from a replenishment tank to a washing tub in a washing machine according to one embodiment.

[0075] Referring to FIGS. 3 to 5, the process of filling the washing tub (20) of a washing machine with gaseous carbon dioxide is described.

[0076] As described above, the washing tub (20) can accommodate a drum (not shown) into which laundry is loaded and which is rotatable. The washing tub (20) can include a laundry inlet for loading laundry into the washing tub (20) and a door for opening and closing the inlet. After opening the door, the user can load laundry into the drum through the laundry inlet. Once the laundry loading is complete, the user can close the door of the washing tub (20).

[0077] The control unit (80) can operate the vacuum pump (120) so that when laundry is placed in the washing tub (20) and the door is closed, air that has entered the washing tub (20) together with the laundry is discharged to the outside of the washing tub (20).

[0078] Referring to FIG. 3, a washing machine according to one embodiment can supply carbon dioxide from a second storage tank (40) to a washing tub (20) after the vacuum pump (120) operates. Hereinafter, a step of increasing the pressure inside the washing tub (20) by filling the washing tub (20) with carbon dioxide, the internal pressure of which has become very low due to the operation of the vacuum pump (120), is referred to as a pressurizing step. The pressurizing step may include a first pressurizing step of supplying carbon dioxide from the second storage tank (40) to the washing tub (20).

[0079] The washing machine may include a first passage (201) connecting a second storage tank (40) and a washing tub (20). Carbon dioxide in the second storage tank (40) may move to the washing tub (20) along the first passage (201). A fifteenth valve (115) and a third valve (103) may be provided on the first passage (201). A first passage connection (301), a second passage connection (302), and a third passage connection (303) may be provided on the first passage (201). The second passage connection (302) may be located downstream of the first passage connection (301) in the first passage (201) connecting the second storage tank (40) and the washing tub (20). The third euro connection (303) may be located downstream from the second euro connection (302) in the first euro (201).

[0080] The 15th valve (115) is provided between the second storage tank (40) and the first flow connection (301) and can open or close the first flow connection (201). The third valve (103) is provided between the third flow connection (303) and the washing tank (20) and can open or close the first flow connection (201).

[0081] In the first pressurization stage, the control unit (80) can open the 15th valve (115) and the 3rd valve (103) to supply carbon dioxide stored in the 2nd storage tank (40) to the washing tub (20). When the 15th valve (115) and the 3rd valve (103) are opened, the pressure inside the 2nd storage tank (40) is approximately 10 to 70 bar and the pressure inside the washing tub (20) is a low pressure close to a vacuum, so that the carbon dioxide inside the 2nd storage tank (40) can move into the washing tub (20) without a separate power source due to the pressure difference between the 2nd storage tank (40) and the washing tub (20).

[0082] In the first pressurization step, the control unit (80) can close the first valve (101) to prevent carbon dioxide from flowing into the second storage tank (40) or moving to the washing tank (20) and to prevent carbon dioxide from flowing into the second storage tank (40) into the first storage tank (10). The first valve (101) can be provided on a flow path connecting the first flow path connection portion (301) and the first storage tank (10).

[0083] In the first pressurization step, the control unit (80) can close the second valve (102) to prevent gaseous carbon dioxide in the supplementary tank (60) having an internal pressure higher than that of the second storage tank (40) from flowing into the second storage tank (40) or moving to the washing tank (20). The second valve (102) can be provided on the flow path connecting the second flow path connection (302) and the supplementary tank (60).

[0084] In the first pressurization stage, the control unit (80) can close the sixth valve (106) to prevent carbon dioxide from moving from the second storage tank (40) to the distillation tank (30). The sixth valve (106) can be provided on the flow path connecting the third flow path connection (303) and the distillation tank (30).

[0085] The control unit (80) can close the 15th valve (115) and the 3rd valve (103) when the pressure inside the washing tub (20) and the pressure inside the second storage tank (40) are in equilibrium. Alternatively, the control unit (80) can close the 15th valve (115) and the 3rd valve (103) before the pressure inside the washing tub (20) and the pressure inside the second storage tank (40) are in equilibrium.

[0086] Referring to FIG. 4, the washing machine can supply carbon dioxide from the first storage tank (10) to the washing tub (20) after the first pressurization step. The pressurization step can include a second pressurization step of supplying carbon dioxide from the first storage tank (10) to the washing tub (20).

[0087] The washing machine may include a second passage (202) connecting a first storage tank (10) and a washing tub (20). Carbon dioxide in the first storage tank (10) may move to the washing tub (20) along the second passage (202). A first valve (101) and a third valve (103) may be provided on the second passage (202). A first passage connection (301), a second passage connection (302), and a third passage connection (303) may be provided on the second passage (202). A portion of the first passage (201) connecting the washing tub (20) from the first passage connection (301) and a portion of the second passage (202) connecting the washing tub (20) from the first passage connection (301) may be the same passage.

[0088] In the second pressurization step, the control unit (80) can open the first valve (101) and the third valve (103) to supply the gaseous carbon dioxide stored in the first storage tank (10) to the washing tub (20). The pressure inside the first storage tank (10) is approximately 30 to 70 bar, and since the pressure inside the washing tub (20) after the first pressurization step is lower than or equal to the pressure inside the second storage tank (40), the gaseous carbon dioxide inside the first storage tank (10) can move into the washing tub (20) without a separate power source due to the pressure difference between the insides of the first storage tank (10) and the washing tub (20).

[0089] In the second pressurization step, the control unit (80) can close the fifteenth valve (115) to prevent gaseous carbon dioxide from flowing into the second storage tank (40) in the first storage tank (10). The fifteenth valve (115) can be provided on a flow path connecting the first flow path connection (301) and the second storage tank (40). The control unit (80) can close the second valve (102) to prevent gaseous carbon dioxide from flowing into the first storage tank (10) in the supplementary tank (60) or gaseous carbon dioxide from flowing into the first storage tank (10) in the supplementary tank (60). In addition, the control unit (80) can close the sixth valve (106) to prevent gaseous carbon dioxide from flowing into the distillation tank (30).

[0090] The control unit (80) can stop the pressurization step if the pressure inside the washing tub (20) rises to a set value of approximately 30 to 60 bar after the first and second pressurization steps described above. If the pressure inside the washing tub (20) does not rise to approximately 30 to 60 bar even after the first and second pressurization steps due to carbon dioxide lost during the carbon dioxide recovery process, a third pressurization step, which will be described later, can be additionally included.

[0091] Referring to FIG. 5, the pressurization step may further include a third pressurization step of supplying carbon dioxide from the replenishment tank (60) to the washing tank (20).

[0092] The washing machine may include a third flow path (203) connecting a replenishment tank (60) and a washing tub (20). Carbon dioxide in the replenishment tank (60) may move to the washing tub (20) along the third flow path (203). A second valve (102) and a third valve (103) may be provided on the third flow path (203). A second flow path connection (302) and a third flow path connection (303) may be provided on the third flow path (203). A portion of the first flow path (201) connecting the washing tub (20) from the second flow path connection (302), a portion of the second flow path (202) connecting the washing tub (20) from the second flow path connection (302), and a portion of the third flow path (203) connecting the washing tub (20) from the second flow path connection (302) may be the same flow path.

[0093] In the third pressurization stage, the control unit (80) can open the second valve (102) and the third valve (103) to supply the gaseous carbon dioxide stored in the supplementary tank (60) to the washing tub (20). Since the pressure inside the supplementary tank (60) is set higher than the set pressure inside the washing tub (20), the gaseous carbon dioxide inside the supplementary tank (60) can be moved to the washing tub (20) without a separate power source due to the pressure difference between the supplementary tank (60) and the washing tub (20).

[0094] In the third pressurization step, the control unit (80) can close the fifteenth valve (115) to prevent gaseous carbon dioxide from flowing into the second storage tank (40) in the supplementary tank (60). The control unit (80) can close the first valve (101) to prevent gaseous carbon dioxide from flowing into the first storage tank (40) or gaseous carbon dioxide from flowing into the supplementary tank (60) in the first storage tank (40). The control unit (80) can close the sixth valve (106) to prevent gaseous carbon dioxide from flowing into the distillation tank (30) in the supplementary tank (60).

[0095] The control unit (80) can close the second valve (102) and the third valve (103) when the pressure inside the washing tank (20) rises to a set value of approximately 30 to 60 bar. When the control unit (80) closes the second valve (102) and the third valve (103), the third pressurization stage can be stopped.

[0096] In one embodiment, the pressurizing step may include the first pressurizing step, the second pressurizing step, and the third pressurizing step. Alternatively, the pressurizing step may include only the first and third pressurizing steps, or only the first and second pressurizing steps. Furthermore, in some cases, the first, second, and third pressurizing steps may be performed in a reversed order.

[0097] Although not shown in the drawing, carbon dioxide in the supplementary tank (60) can be supplied to the first storage tank (10) or the second storage tank (40). The second valve (102) and the first valve (101) can be opened, and the third valve (103), the sixth valve (106), and the fifteenth valve (115) can be closed, so that carbon dioxide in the supplementary tank (60) moves to the first storage tank (10). The second valve (102) and the fifteenth valve (115) can be opened, and the third valve (103), the sixth valve (106), and the first valve (101) can be closed, so that carbon dioxide in the supplementary tank (60) moves to the second storage tank (40).

[0098] FIG. 6 is a conceptual diagram illustrating a flow path of liquid carbon dioxide moving from a first storage tank to a washing tub in a washing machine according to one embodiment.

[0099] Referring to Fig. 6, the washing machine can supply carbon dioxide to the washing tub (20) after the pressurization step. The washing machine can include a fourth passage (204) connecting the first storage tank (10) and the washing tub (20). The fourth passage (204) is a liquid passage through which liquid carbon dioxide mainly moves, and may refer to a passage different from the second passage (202), which is a gas passage through which gaseous carbon dioxide mainly moves. Liquid carbon dioxide and gaseous carbon dioxide coexist inside the washing tub (20), and depending on temperature and pressure conditions, the liquid carbon dioxide can be vaporized or the gaseous carbon dioxide can be liquefied. Accordingly, the liquid carbon dioxide and gaseous carbon dioxide can move together along the fourth passage (204), and the gaseous carbon dioxide and liquid carbon dioxide can move together along the second passage (202). A fourth valve (104) may be provided on the fourth passage (204). The fourth valve (104) may be arranged to open and close the fourth flow path (204).

[0100] The washing machine can supply the liquid carbon dioxide stored in the first storage tank (10) to the washing tub (20). As described above, since the first storage tank (10) is positioned higher than the washing tub (20), the liquid carbon dioxide in the first storage tank (10) can move to the washing tub (20) by gravity without a separate power source. The control unit (80) can open the fourth valve (104) to supply the liquid carbon dioxide in the first storage tank (10) to the washing tub (20). When the control unit (80) opens the fourth valve (104), the liquid carbon dioxide inside the first storage tank (10) can move to the washing tub (20) by gravity.

[0101] After liquid carbon dioxide is supplied to the washing tub (20), the drum rotates, allowing washing to proceed. Liquid carbon dioxide has a lower viscosity than water, allowing it to easily penetrate between fibers and remove contaminants. During this process, foreign substances in the laundry may dissolve in the liquid carbon dioxide. Some of these foreign substances in the laundry may not dissolve in the liquid carbon dioxide due to their different polarity from carbon dioxide.

[0102] FIG. 7 is a conceptual diagram illustrating a path of gaseous carbon dioxide moving from a washing tank to a distillation tank and a path of liquid carbon dioxide moving from a washing tank to a distillation tank in a washing machine according to one embodiment.

[0103] Referring to Fig. 7, when washing is completed, the washing machine can discharge liquid carbon dioxide and foreign substances inside the washing tub (20) into the distillation tank (30). At this time, in order to eliminate the pressure difference between the inside of the washing tub (20) and the inside of the distillation tank (30), the control unit (80) can open the third valve (103) and the sixth valve (106). The third valve (103) and the sixth valve (106) can be provided on the fifth passage (205) connecting the washing tub (20) and the distillation tank (30). The fifth passage (205) is a gas passage, and a third passage connection (303) can be provided in the fifth passage (205). The third valve (103) can be provided upstream of the third passage connection (303) in the fifth passage (205). The sixth valve (106) can be provided downstream of the third flow connection (303) in the fifth flow (205).

[0104] The control unit (80) can open the fifth valve (105) to discharge liquid carbon dioxide and foreign substances inside the washing tank (20) to the distillation tank (30). The fifth valve (105) can be provided on the sixth passage (206) connecting the washing tank (20) and the distillation tank (30). The sixth passage (206) can be a liquid passage through which liquid carbon dioxide and foreign substances move. The fifth valve (105) can be provided to open or close the sixth passage (206).

[0105] The distillation tank (30) may be placed below the washing tank (20). This is to ensure that when the fifth valve (105) is opened, the liquid carbon dioxide and foreign substances inside the washing tank (20) move to the distillation tank (30) by gravity without a separate power source.

[0106] FIG. 8 is a conceptual diagram illustrating a process of recovering carbon dioxide inside a distillation tank to a first storage tank in a washing machine according to one embodiment.

[0107] Referring to Fig. 8, the washing machine can recover carbon dioxide discharged from the washing tank (20) to the distillation tank (30) into the first storage tank (10).

[0108] The washing machine can recover gaseous carbon dioxide inside the distillation tank (30) to the first storage tank (10), or can vaporize liquid carbon dioxide inside the distillation tank (30) and then recover it to the first storage tank (10).

[0109] The washing machine may include a seventh passage (207) connecting the input terminal of the distillation tank (30) and the compressor (50). A seventh valve (107) may be provided on the seventh passage (207). A fourth passage connection (304) may be provided on the seventh passage (207). The fourth passage connection (304) may be located downstream of the seventh valve (107). The fourth passage connection (304) may be connected to the washing tank (20). The fourth passage connection (304) may connect the tenth passage (210) and the seventh passage (207).

[0110] The control unit (80) can move the gaseous carbon dioxide inside the distillation tank (30) to the input terminal of the compressor (50) by opening the seventh valve (107). When the seventh valve (107) is opened, the gaseous carbon dioxide in the distillation tank (30) can move along the seventh flow path (207) and flow into the input terminal of the compressor (50).

[0111] The washing machine may include an eighth passage (208) connecting the output terminal of the compressor (50) and the sixth passage connection (306). The eighth passage (208) may be provided with a fifth passage connection (305), an eighth valve (108), and a ninth valve (109). The eighth passage (208) may include a distillation tank heat exchanger (208a). The eighth valve (108) may be provided downstream of the fifth passage connection (305). The ninth valve (109) may be provided downstream of the eighth valve (108). The distillation tank heat exchanger (208a) may be provided between the eighth valve (108) and the ninth valve (109), and may be provided to pass through the distillation tank (30). The 6th euro connection (306) may refer to the point where the 8th euro (208), the 9th euro (209), the 11th euro (211), and the 12th euro (212) are connected to each other.

[0112] The control unit (80) can open the eighth valve (108) and the ninth valve (109). When the eighth valve (108) and the ninth valve (109) are opened, the high temperature and high pressure gaseous carbon dioxide that has passed through the compressor (50) can move to the distillation tank heat exchanger (208a). The distillation tank heat exchanger (208a) is a part of the eighth flow path (208) and can pass through the interior of the distillation tank (208) or the exterior of the distillation tank (208) adjacent to the distillation tank (208). As described above, the high temperature carbon dioxide that has passed through the compressor (50) can flow into the distillation tank heat exchanger (208a). As a result, the distillation tank heat exchanger (208a) can maintain a high temperature. The distillation tank heat exchanger (208a) can supply heat to the interior or exterior of the distillation tank (30). Liquid carbon dioxide inside the distillation tank (30) can be vaporized by heat supplied to the distillation tank (30) from the distillation tank heat exchanger (208a). Liquid carbon dioxide and foreign substances dissolved in the liquid carbon dioxide can be accommodated inside the distillation tank (30). As the liquid carbon dioxide vaporizes inside the distillation tank (30), foreign substances dissolved in the liquid carbon dioxide can be separated from the carbon dioxide. The foreign substances separated from the carbon dioxide can be discharged from the distillation tank (30) to the foreign substance tank (70) by opening the 16th valve (116). For this purpose, the control unit (80) can open the 16th valve (116).

[0113] The control unit (80) can open the 13th valve (113). When the 8th valve (108) and the 9th valve (109) are opened, carbon dioxide that has passed through the distillation tank heat exchanger (208a) from the output terminal of the compressor (50) can move to the 6th flow path connection (306). When the 13th valve (113) is opened, carbon dioxide that has moved to the 6th flow path connection (306) can flow into the first storage tank (10). At this time, the control unit (80) can close the 12th valve (112) and the 14th valve (114) so ​​that carbon dioxide that has moved to the 6th flow path connection (306) does not move to the 11th flow path (211) and the 12th flow path (212) which will be described later.

[0114] Additionally, before gaseous carbon dioxide flows into the first storage tank (10) from the sixth connection (306), it can be heat-exchanged with a chiller (11) or an external heat exchanger, and through this, it can be liquefied into liquid carbon dioxide and flowed into the first storage tank (10).

[0115] As described above, in order to recover carbon dioxide inside the distillation tank (30) to the first storage tank (10), the control unit (80) can open the seventh valve (107), the eighth valve (108), the ninth valve (109), and the thirteenth valve (13). In addition, the control unit (80) can control the compressor (50) so that the compressor (50) operates.

[0116] FIG. 9 is a conceptual diagram illustrating a process of recovering carbon dioxide inside a washing machine tub to a first storage tank according to one embodiment.

[0117] Referring to FIG. 9, a depressurization step for depressurizing the inside of the washing tub (20) to remove laundry from the washing tub (20) after washing is completed is described.

[0118] The depressurization step may refer to a step of lowering the pressure inside the washing tub (20) to 1 to 1.5 bar, which is a level similar to atmospheric pressure. The depressurization step may include a first depressurization step of lowering the pressure inside the washing tub (20) by recovering carbon dioxide inside the washing tub (20) to the first storage tank (10).

[0119] Referring to FIG. 9, the washing machine may include a tenth passage (210) connecting the washing tub (20) and the input terminal of the compressor (50). A tenth valve (110) may be provided on the tenth passage (210). A fourth passage connection (304) may be provided on the tenth passage (210). The fourth passage connection (304) may be provided downstream of the tenth valve (110). The fourth passage connection (304) may be connected to the distillation tank (30). The tenth passage (210) and the seventh passage (207) may be connected at the fourth passage connection (304).

[0120] The washing machine may include an eleventh passage (211) connecting the output terminal of the compressor (50) and the sixth passage connection (306). The eleventh passage (211) may include a washing tub heat exchanger (211a). The eleventh passage (211) may be provided with an eleventh valve (111) and a twelfth valve (112). The eleventh valve (111) may be located upstream of the twelfth valve (112), and the washing tub heat exchanger (211a) may be provided between the eleventh valve (111) and the twelfth valve (112). The washing tub heat exchanger (211a) may be a part of the eleventh passage (211) and may pass through the interior of the washing tub (20) or the exterior of the washing tub (20) adjacent to the washing tub (20).

[0121] Referring to Fig. 9, in the first pressure reduction step, the control unit (80) can open the tenth valve (110). When the tenth valve (110) is opened, carbon dioxide inside the washing tank (20) can move along the tenth passage (210) and flow into the input terminal of the compressor (50).

[0122] In the first depressurization stage, the control unit (80) can open the eleventh valve (111). When the eleventh valve (111) is opened, the high temperature and high pressure carbon dioxide discharged to the output terminal of the compressor (50) can move along the eleventh passage (211), pass through the washing tank heat exchanger (211a), and move to the sixth passage connection (306).

[0123] Since high-temperature carbon dioxide that has passed through the compressor (50) flows inside the washing tub heat exchange unit (211a), the washing tub heat exchange unit (211a) can maintain a high temperature. The washing tub heat exchange unit (211a) can supply heat to the inside or outside of the washing tub (20). The heat supplied to the washing tub (20) from the washing tub heat exchange unit (211a) can prevent the laundry inside the washing tub (20) from being damaged due to moisture condensation.

[0124] As described above, after putting laundry into the washing tub (20), the washing tub door is closed and the vacuum pump (120) is operated to create a low-pressure state close to a vacuum inside the washing tub (20). However, the inside of the washing tub (20) is not a complete vacuum, and some air may remain inside the washing tub (20). The air remaining inside the washing tub (20) contains moisture, and this moisture may condense in the process of lowering the pressure inside the washing tub (20). This is because when the pressure inside the washing tub (20) is lowered, the temperature inside the washing tub (20) is lowered.

[0125] If moisture that has penetrated into the laundry condenses, the laundry may be damaged. To prevent this, the temperature inside the washing tub (20) must be maintained above zero even during the depressurization step. For example, the temperature inside the washing tub (20) can be maintained at approximately 10 degrees Celsius or higher. A separate heater may be included to increase the temperature inside the washing tub (20), but this is not energy efficient. Therefore, the washing machine according to the present disclosure can supply heat to the inside of the washing tub (20) using the heat of high-temperature carbon dioxide that has passed through the compressor (50). Specifically, heat can be supplied to the washing tub (20) by allowing the path through which the high-temperature carbon dioxide that has passed through the compressor (50) flows to pass through the inside or outside of the washing tub (20).

[0126] In the first depressurization stage, the control unit (80) can open the 13th valve (113). When the 13th valve (113) is opened, the carbon dioxide that has moved to the 6th flow path connection (306) can move to the first storage tank (10) along the 9th flow path (209). The 9th flow path (209) can connect the 6th flow path connection (306) and the first storage tank (10). The 13th valve (113) can be provided on the 9th flow path (209).

[0127] By opening the 10th valve (110), the 11th valve (111), the 12th valve (112), and the 13th valve (113), carbon dioxide discharged from the washing tub (20) can move to the first storage tank (10) via the compressor (50). The paths (210, 211, 209) connecting the washing tub (20), the compressor (50), and the first storage tank (10) so that carbon dioxide discharged from the washing tub (20) can move to the first storage tank (10) via the compressor (50) are referred to as the first washing tub recovery path.

[0128] In the first depressurization step, which is the initial step of depressurizing the inside of the washing tank (20), carbon dioxide inside the washing tank (20) can be recovered into the first storage tank (10).

[0129] Immediately after the washing is completed, the internal pressure of the washing tub (20) is high, so it is easy to recover carbon dioxide to the first storage tank (10) where the internal pressure of the washing tub (20) and the pressure difference are relatively small. This is because the pressure difference between the input and output terminals of the compressor (50) is relatively small. Since the input terminal of the compressor (50) is connected to the washing tub (20) and the output terminal of the compressor (50) is connected to the first storage tank (10), when the pressure difference between the washing tub (20) and the first storage tank (10) is small, the pressure difference between the input and output terminals of the compressor (50) is also small, so that the load on the compressor (50) is small.

[0130] As the first depressurization step progresses, the carbon dioxide inside the washing tub (20) is recovered into the first storage tank (10), and the pressure inside the washing tub (20) gradually decreases. As the pressure inside the washing tub (20) decreases and the pressure inside the first storage tank (10) is maintained at a constant level, the load on the compressor (50) may gradually increase. If the load on the compressor (50) is excessive, the compressor (50) may be damaged.

[0131] FIG. 10 is a conceptual diagram illustrating a process of recovering carbon dioxide inside a washing machine tub to a second storage tank according to one embodiment.

[0132] Referring to FIG. 10, a second decompression step according to one embodiment is described.

[0133] The depressurization step may include a second depressurization step for lowering the pressure inside the washing tank (20) by recovering the carbon dioxide inside the washing tank (20) to the second storage tank (40) rather than the first storage tank (10) after the first depressurization step.

[0134] In the second depressurization stage, the control unit (80) can open the 14th valve (114) and close the 13th valve (113). When the 14th valve (114) is opened, the carbon dioxide that has moved to the 6th flow connection (306) can move to the 2nd storage tank (40). When the 13th valve (113) is closed, the carbon dioxide that has moved to the 6th flow connection (306) cannot move to the 1st storage tank (10).

[0135] By opening the 14th valve (114) and closing the 13th valve (113), carbon dioxide discharged from the washing tub (20) can move to the second storage tank (40) via the compressor (50). The paths (210, 211, 212) connecting the washing tub (20), the compressor (50), and the second storage tank (40) so that carbon dioxide discharged from the washing tub (20) can move to the second storage tank (40) via the compressor (50) are referred to as the second washing tub recovery path.

[0136] As described above, as the first depressurization step progresses, the pressure inside the washing tank (20) gradually decreases, and the pressure difference with respect to the pressure inside the first storage tank (10) may gradually increase. As a result, the pressure difference between the input and output terminals of the compressor (50) may increase, and the load on the compressor (50) may gradually increase.

[0137] According to the present disclosure, the load on the compressor (50) can be reduced by including a second depressurization step after the first depressurization step. By reducing the load on the compressor (50), damage to the compressor (50) can be prevented.

[0138] The internal pressure of the second storage tank (40) can be maintained at a lower level than the internal pressure of the first storage tank (10). When the internal pressure of the washing tub (20) is lowered, the pressure difference between the washing tub (20) and the second storage tank (40) is smaller than the pressure difference between the washing tub (20) and the first storage tank (10). When the 14th valve (114) is opened, the input end of the compressor (50) is connected to the washing tub (20) and the output end of the compressor (50) is connected to the second storage tank (40), so that the pressure difference between the input end and the output end of the compressor (50) can be smaller than that during the first pressure reduction stage. This means that the load on the compressor (50) is reduced, and since the compressor (50) does not operate excessively, the lifespan of the compressor (50) can be prevented from being reduced.

[0139] According to the present disclosure, after washing is completed, the depressurization step for depressurizing the inside of the washing tub (20) includes the first depressurization step and the second depressurization step, thereby reducing the load on the compressor (50), preventing damage to the compressor (50), and extending the life of the compressor (50). In addition, the inside of the washing tub (20) can be depressurized with only one compressor (50) without overloading the compressor (50). By including only one compressor (50), the configuration of the washing machine can be relatively simple, and noise and noise caused by the compressor (50) can be reduced compared to a washing machine including a plurality of compressors (50).

[0140] According to one embodiment, a washing machine includes a washing tub configured to wash laundry using carbon dioxide, a compressor configured to compress carbon dioxide discharged from the washing tub, a first storage tank connected to the compressor and configured to store carbon dioxide, a second storage tank connected to the compressor and configured to store carbon dioxide, a first flow path connecting the compressor and the first storage tank, a second flow path connecting the compressor and the second storage tank, a first valve configured to open and close the first flow path, a second valve configured to open and close the second flow path, the compressor, and a control unit configured to control the first valve and the second valve.

[0141] The above first storage tank may be configured to store carbon dioxide at a first pressure level.

[0142] The second storage tank may be configured to store carbon dioxide at a second pressure level lower than the first pressure level.

[0143] The control unit operates the compressor to recover carbon dioxide inside the washing tub when washing is completed, opens the first valve so that carbon dioxide discharged from the compressor moves to the first storage tank, closes the first valve and opens the second valve so that carbon dioxide discharged from the compressor moves to the second storage tank based on the pressure inside the washing tub.

[0144] The above control unit can open the first valve when the pressure inside the washing tank is higher than the pressure reduction reference pressure.

[0145] The above control unit can close the first valve and open the second valve when the pressure inside the washing tank is lower than the pressure reduction reference pressure.

[0146] The control unit can open the first valve when the difference between the pressure inside the washing tank and the pressure inside the first storage tank is less than a predetermined pressure.

[0147] The control unit can close the first valve and open the second valve when the difference between the pressure inside the washing tank and the pressure inside the first storage tank is greater than the predetermined pressure.

[0148] The above control unit can close the first valve and open the second valve after a predetermined time has passed after opening the first valve.

[0149] The above control unit can close the first valve and open the second valve when the power consumption of the compressor is greater than a predetermined value.

[0150] The first flow path may include a third flow path connecting a point on the first flow path from the compressor, and a fourth flow path connecting the point to the first storage tank.

[0151] The second euro may include the third euro and the fifth euro connecting the second storage tank from the point on the first euro.

[0152] The above first valve may be configured to open and close the fourth flow path.

[0153] The above second valve may be configured to open and close the fifth flow path.

[0154] The third flow may include a washing tub heat exchanger that passes through the washing tub to supply heat to the washing tub.

[0155] The washing machine may further include a third passage connecting the second storage tank and the washing tub, a fourth passage connecting the first storage tank and the washing tub, a third valve configured to open and close the third passage, and a fourth valve configured to open and close the fourth passage.

[0156] The above control unit can open the third valve so that carbon dioxide in the second storage tank moves to the washing tank when supplying carbon dioxide to the washing tank.

[0157] The control unit can close the third valve and open the fourth valve based on the pressure inside the washing tank so that carbon dioxide in the first storage tank moves to the washing tank.

[0158] The above control unit can open the third valve and close the third valve and open the fourth valve when the pressure inside the washing tank and the pressure inside the second storage tank are equilibrated.

[0159] The above control unit can open the third valve and, when the pressure inside the washing tank becomes higher than a predetermined pressure, close the third valve and open the fourth valve.

[0160] The washing machine may further include a supplementary tank storing carbon dioxide at a third pressure level higher than the second pressure level to supply carbon dioxide to the washing tub, a fifth passage connecting the supplementary tank and the washing tub, and a fifth valve configured to open and close the fifth passage.

[0161] The control unit can open the fourth valve, and if the pressure inside the washing tub is lower than a predetermined pressure after a predetermined period of time, close the third valve and the fourth valve and open the fifth valve.

[0162] The washing machine may further include a first euro connection part where the third euro and the fourth euro are joined.

[0163] The third valve may be provided on the flow path connecting the first flow path connection portion and the second storage tank.

[0164] The above fourth valve may be provided on the flow path connecting the first flow path connection portion and the first storage tank.

[0165] According to one embodiment, a control method for a washing machine including a first storage tank, a second storage tank different from the first storage tank, and a washing tub includes the steps of supplying carbon dioxide from the first storage tank and the second storage tank to the washing tub to wash laundry, and, after washing is completed, depressurizing the inside of the washing tub to open the washing tub and recovering carbon dioxide inside the washing tub. The step of recovering carbon dioxide inside the washing tub includes the steps of moving carbon dioxide inside the washing tub to the first storage tank, and the steps of moving carbon dioxide inside the washing tub to the second storage tank.

[0166] Carbon dioxide inside the washing tank can be moved to the first storage tank, and when the pressure inside the washing tank is higher than the decompression standard, carbon dioxide inside the washing tank can be moved to the second storage tank.

[0167] If the pressure inside the washing tank is higher than the decompression reference pressure, the carbon dioxide inside the washing tank can be moved to the first storage tank.

[0168] If the pressure inside the washing tank is lower than the decompression reference pressure, the carbon dioxide inside the washing tank can be moved to the second storage tank.

[0169] The step of supplying carbon dioxide from the first storage tank and the second storage tank to the washing tub may include a step of supplying carbon dioxide from the second storage tank to the washing tub and a step of supplying carbon dioxide from the first storage tank to the washing tub.

[0170] Carbon dioxide is supplied from the second storage tank to the washing tank, and when the pressure inside the washing tank and the pressure inside the second storage tank are equilibrated, carbon dioxide can be supplied from the first storage tank to the washing tank.

[0171] Carbon dioxide can be supplied from the second storage tank to the washing tank, and when the pressure inside the washing tank becomes higher than a predetermined pressure, carbon dioxide can be supplied from the first storage tank to the washing tank.

[0172] The internal pressure of the second storage tank may be set lower than the internal pressure of the first storage tank.

[0173] According to the present disclosure, a washing machine can be provided that can depressurize the inside of a washing tub with only one compressor after a washing cycle by including two carbon dioxide storage tanks having different internal pressures.

[0174] According to the present disclosure, a washing machine can be provided that can prevent overload of a compressor by recovering carbon dioxide inside a washing tank by dividing it into a first storage tank and a second storage tank.

[0175] The above illustrates and describes specific embodiments. However, the invention is not limited to the above-described embodiments, and those skilled in the art will readily appreciate that various modifications and implementations can be made without departing from the spirit and scope of the invention as set forth in the claims below.

Claims

1. A washing tub designed to wash laundry using carbon dioxide; A compressor connected to the above washing tank and arranged to compress carbon dioxide; A first storage tank provided to store carbon dioxide; A second storage tank provided to store carbon dioxide; A first flow path connecting the above compressor and the first storage tank; A second passage connecting the compressor and the second storage tank; A first valve provided to open and close the first euro; A second valve provided to open and close the second euro; and Including a control unit configured to control the compressor, the first valve, and the second valve; The above control unit, When the washing is completed, the compressor is operated to compress the carbon dioxide recovered from the washing tub, Opening the first valve so that the compressed carbon dioxide moves from the compressor along the first path to the first storage tank, A washing machine that closes the first valve and opens the second valve so that compressed carbon dioxide moves from the compressor to the second storage tank along the second path based on the pressure inside the washing tank.

2. In paragraph 1, The above first storage tank is provided to store carbon dioxide at a first pressure level, A washing machine wherein the second storage tank is configured to store carbon dioxide at a second pressure level lower than the first pressure level.

3. In paragraph 1, The above control unit, If the pressure inside the washing tank is higher than the pressure relief standard pressure, the first valve is opened, A washing machine that closes the first valve and opens the second valve when the pressure inside the washing tank is lower than the pressure reduction reference pressure.

4. In paragraph 1, The above control unit, If the pressure difference between the inside of the washing tank and the inside of the first storage tank is less than a predetermined pressure difference, the first valve is opened, A washing machine that closes the first valve and opens the second valve when the pressure difference between the inside of the washing tub and the inside of the first storage tank is greater than the predetermined pressure difference.

5. In paragraph 1, The above control unit, A washing machine that closes the first valve and opens the second valve after a predetermined time has passed after opening the first valve.

6. In paragraph 1, The above first euro is, Including a third passage connecting the compressor and a point on the first passage, and a fourth passage connecting the point on the first passage and the first storage tank, The above second euro is, A washing machine including a third euro and a fifth euro connecting the point on the first euro and the second storage tank.

7. In paragraph 6, The above first valve is provided to open and close the fourth euro, A washing machine in which the second valve is configured to open and close the fifth euro.

8. In paragraph 6, The third euro is a washing machine including a washing tub heat exchanger that passes through the washing tub to supply heat to the washing tub.

9. In paragraph 1, A third flow path connecting the second storage tank and the washing tank; A fourth passage connecting the first storage tank and the washing tank; A third valve provided to open and close the third euro; and Further comprising a fourth valve configured to open and close the fourth euro; The above control unit, Open the third valve so that the carbon dioxide in the second storage tank moves to the washing tank along the third path, A washing machine that closes the third valve and opens the fourth valve so that carbon dioxide in the first storage tank moves to the washing tank along the fourth path based on the pressure inside the washing tank.

10. In paragraph 9, The above control unit, A washing machine that opens the third valve and closes the third valve and opens the fourth valve when the pressure inside the washing tub and the pressure inside the second storage tank reach equilibrium.

11. In paragraph 9, The above control unit, A washing machine that opens the third valve and closes the fourth valve when the pressure inside the washing tub becomes higher than a predetermined pressure.

12. In paragraph 9, A supplementary tank for storing carbon dioxide at a third pressure level higher than the second pressure level, which is the pressure level of carbon dioxide stored in the second storage tank; A fifth path connecting the above supplementary tank and the above washing tank; and Further comprising a fifth valve configured to open and close the fifth euro; The above control unit, A washing machine that opens the fourth valve, closes the third valve and the fourth valve, and opens the fifth valve when the pressure inside the washing tub is lower than a predetermined pressure after a predetermined period of time.

13. In paragraph 9, Further comprising a first euro connection part where the third euro and the fourth euro are combined; The third valve is provided on a portion of the third flow path connecting the first flow path connection part and the second storage tank, A washing machine in which the fourth valve is provided on a portion of the fourth passage connecting the first passage connection part and the first storage tank.

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