Washer dryer

Abstract

To provide a washing and drying machine capable of detecting both intrusion of bubbles into a circulation air passage and a corrosion state of a heat exchanger.SOLUTION: A washing and drying machine includes a washing tub, a heat pump unit, a circulation air passage, a control part, and a corrosion current sensor. The washing tub is elastically supported in a housing, and the heat pump unit has a heat exchanger including an evaporator and a condenser, and blows air to the washing tub 3. The circulation air passage 24 is connected to the heat exchanger of the heat pump unit 6 and the washing tub. The corrosion current sensor is arranged at the heat exchanger which bubbles of a detergent which has been generated in the washing tub and entered the circulation air passage can be attached to, or at a predetermined position at which the bubbles of the detergent which has been generated in the washing tub and entered the circulation can be attached to, in the vicinity of the heat exchanger and in the circulation air passage.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] For example, Patent Document 1 discloses a washing and drying machine including a dehumidifying heat exchanger and a heating heat exchanger. The washing and drying machine described in Patent Document 1 includes an exhaust air passage that guides air from a water tank to the dehumidifying heat exchanger and the heating heat exchanger, and an intake air passage that guides air from the dehumidifying heat exchanger and the heating heat exchanger to the water tank, and forms a circulation air passage. Nozzles as water spraying means for eliminating detergent foam are arranged in the exhaust air passage and the intake air passage near the inlet side and the outlet side of the circulation air passage with respect to a drum rotatably installed inside the water tank. Thereby, it is possible to prevent the detergent foam from adhering to the dehumidifying heat exchanger and the heating heat exchanger through the circulation air passage, and to prevent a decrease in drying performance.

[0003] Further, Patent Document 2 describes a foam detection device including an electrode pair for detecting foam flowing into a warm air passage during abnormal foaming.

[0004] Further, Patent Document 3 describes a refrigeration cycle device used in an air conditioner, and an ACM sensor that reproduces and detects a corrosion current regarding corrosion occurring in the piping of the refrigeration cycle device is described. Examples of the cause of piping corrosion include termite nest corrosion caused by carboxylic acid oxidized from formaldehyde used in building materials, and stress corrosion cracking caused by ammonia contained in pet urine, etc.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

[0006] However, in cases such as when the amount of water sprayed is insufficient in the washing machine described in Patent Document 1, or when foam enters from the upstream side of the air passage in the washing machine described in Patent Document 2, foam may reach the heat exchanger, making it impossible to determine the extent to which each heat exchanger is corroded by detergent foam.

[0007] Therefore, the purpose of this disclosure is to solve the above problems by providing a washing and drying machine that can detect both the intrusion of foam into the circulating air passage and the corrosion status of the heat exchanger. [Means for solving the problem]

[0008] A washing machine and dryer according to one aspect of the present disclosure comprises a washing tub, a heat pump unit, a circulating air passage, a control unit, and a corrosion current sensor. The washing tub is elastically supported within a housing, and the heat pump unit has a heat exchanger including an evaporator and a condenser, which blows hot air into the washing tub. The circulating air passage is connected to the heat exchanger of the heat pump unit and the washing tub. The control unit controls a washing operation including a washing process, a rinsing process, and a spin-drying process, and a drying operation including a drying process. The corrosion current sensor is positioned on the heat exchanger, or in the circulating air passage near the heat exchanger, at a predetermined location where detergent foam generated in the washing tub and entering the circulating air passage can adhere to it. [Effects of the Invention]

[0009] According to this disclosure, it is possible to provide a washing and drying machine that can detect both the intrusion of foam into the circulating air passage and the corrosion status of the heat exchanger. [Brief explanation of the drawing]

[0010] [Figure 1] Schematic cross-sectional view of a washing machine and dryer according to Embodiment 1 of this disclosure [Figure 2] schematic cross-sectional view of the inside of the circulating air duct. [Figure 3] Schematic plan sectional view inside the circulation air path [Figure 4A] Schematic diagram showing an example of a heat pump unit [Figure 4B] Schematic partial perspective view showing an example of an evaporator and a condenser [Figure 5] Schematic diagram of an ACM sensor [Figure 6] Cross-sectional view of an ACM sensor with a water film attached [Figure 7] Graph showing the change profiles of temperature and humidity [Figure 8] Graph showing the change in corrosion current in each liquid agent under the conditions of Figure 9 [Figure 9] Graph showing the relative humidity dependence in each liquid agent [Figure 10] Graph showing the change in corrosion rate with respect to the thickness of the water film [Figure 11] Graph showing the profile of temperature change when the drying operation is not performed [Figure 12] Graph showing the time progression of corrosion current when the drying operation is not performed [Figure 13] Graph showing the profile of temperature change when the drying operation is performed [Figure 14] Graph showing the time progression of corrosion current when the drying operation is performed [Figure 15] Graph showing the time progression of the integrated charge amount [Figure 16] Block diagram of the washing and drying system of Embodiment 2

Mode for Carrying Out the Invention

[0011] The washing and drying machine according to the first aspect of the present disclosure includes a washing tub, a heat pump unit, a circulation air passage, a control unit, and a corrosion current sensor. The washing tub is elastically supported inside the housing. The heat pump unit has a heat exchanger including an evaporator and a condenser, and blows warm air into the washing tub. The circulation air passage is connected to the heat exchanger of the heat pump unit and the washing tub. The control unit controls a washing operation including a washing step, a rinsing step, and a dehydration step, and a drying operation including a drying step. The corrosion current sensor is disposed at a predetermined position on the heat exchanger or in the circulation air passage near the heat exchanger where bubbles of the detergent generated in the washing tub and entering the circulation air passage can adhere.

[0012] Since the corrosion current sensor is disposed at a predetermined position on the heat exchanger or in the circulation air passage near the heat exchanger where bubbles of the detergent entering the circulation air passage can adhere, the corrosion condition of the heat exchanger can be estimated from the detection result of the corrosion current sensor, and it can be applied to a system for preventing shortening of the life of the heat exchanger and predicting a failure.

[0013] According to the second aspect of the present disclosure, in the washing and drying machine of the first aspect, the heat exchanger includes a heat exchanger pipe through which a refrigerant flows, and the predetermined position is an exposed surface of the heat exchanger pipe exposed to the circulation air passage.

[0014] When bubbles of the detergent abnormally occur during the washing step, there is a possibility that the bubbles enter the circulation air passage and reach either the upstream end or the downstream end of the heat exchanger. In this case, since the corrosion current sensor is disposed at the exposed portion of the heat exchanger pipe, which is a metal pipe that is likely to corrode among the heat exchangers, the corrosion current can be monitored at a position where corrosion is likely to progress.

[0015] According to the third aspect of the present disclosure, in the washing and drying machine of the first aspect, the heat exchanger includes fins with which air flowing along the circulation air passage comes into contact, and the predetermined position is an exposed surface of the fins.

[0016] Since the corrosion current sensor is disposed on the exposed surface of the fins of the heat exchanger, it is possible to accurately detect that the bubbles have reached the heat exchanger.

[0017] According to a fourth aspect of this disclosure, in the washing and drying machine of the first aspect, the predetermined position is the wall surface of the circulating air passage near the upstream side of the evaporator, or the wall surface of the circulating air passage near the downstream side of the condenser.

[0018] Since corrosion current sensors are placed on the wall of the circulating air passage near the upstream side of the evaporator, or on the wall of the circulating air passage near the downstream side of the condenser, it is possible to accurately detect when bubbles have reached the heat exchanger.

[0019] According to a fifth aspect of this disclosure, in a washing and drying machine of any of the first to fourth aspects, the corrosion current sensor is configured as a foam sensor for detecting abnormal foam generation.

[0020] Since the corrosion current sensor is configured as a foam sensor, it can detect the abnormal occurrence of foam that reaches the heat exchanger.

[0021] According to the sixth aspect of this disclosure, in a washing and drying machine of any of the first to fifth aspects, the corrosion current sensor includes an ACM (Atmospheric Corrosion Monitor) sensor.

[0022] Since the cathode electrode of an ACM sensor is made of a material with a higher potential than the anode electrode, the progression of corrosion can be directly and quantitatively evaluated by analyzing the output of the ACM sensor.

[0023] According to the seventh aspect of this disclosure, in a washer-dryer according to any of the first to fourth aspects, if the user has not set a drying operation after the washing operation, and the corrosion current sensor detects a corrosion current of a predetermined value or higher during the washing operation, the control unit performs an airflow drying operation that suppresses drying inside the washing tub after the washing operation is completed.

[0024] If the corrosion current sensor detects a corrosion current exceeding a predetermined value, it is assumed that foam has reached the heat exchanger. Therefore, even if a drying cycle after the wash cycle is not set, the progression of corrosion can be suppressed by drying the heat exchanger with an airflow drying operation that suppresses drying inside the washing tub after the wash cycle is completed. Furthermore, since the drying operation is performed automatically, there is no need for the user to perform any extra operations.

[0025] According to the eighth aspect of this disclosure, in a washing dryer according to any of the first to seventh aspects, a water spraying unit is provided for spraying water onto a heat exchanger, and the control unit includes control of a water spraying operation to spray water from the water spraying unit, and when a corrosion current sensor detects a corrosion current of a predetermined value or higher, the control unit performs the water spraying operation.

[0026] If the corrosion current sensor detects a corrosion current exceeding a predetermined value, it is assumed that foam has reached the heat exchanger. In this case, the control unit performs an airflow drying operation after the washing cycle is completed, which allows the moisture from the foam adhering to the heat exchanger to evaporate and suppress the progression of corrosion of the heat exchanger. Furthermore, since the airflow drying operation is a drying operation that suppresses drying inside the washing tub, power consumption can be saved.

[0027] According to the ninth aspect of this disclosure, in the washing and drying machine of the eighth aspect, the control unit performs a water spraying operation after the washing operation is completed.

[0028] After the washing cycle is complete, a watering cycle is automatically performed, spraying water onto the heat exchanger and washing away foam, which helps to suppress the progression of corrosion in the heat exchanger.

[0029] According to a tenth aspect of this disclosure, in a washing and drying machine of the eighth or ninth aspect, if the user has not set a drying operation after the washing operation, the control unit performs an airflow drying operation that suppresses drying inside the washing tub after the water spraying operation.

[0030] Even if the user has not set a drying operation, the corrosion of the heat exchanger can be further suppressed by automatically performing airflow drying operation after flushing out foam from the heat exchanger with water spraying operation.

[0031] According to the eleventh aspect of this disclosure, a washing and drying machine according to any of the first to seventh aspects includes a water spraying unit that sprays water onto a heat exchanger and a notification unit that transmits information to the user. The control unit includes control of the water spraying operation that causes water to be sprayed from the water spraying unit, and when a corrosion current sensor detects a corrosion current of a predetermined value or higher, the notification unit notifies the user of the instruction to perform a drying operation or a water spraying operation.

[0032] Even if drying or watering operations are not performed automatically, prompting the user to perform these operations can suppress the progression of corrosion in the heat exchanger.

[0033] According to a twelfth aspect of the present disclosure, a washing machine and dryer of the fourth aspect comprises a filter located upstream of the evaporator in the circulating air passage, and a blower located downstream of the condenser in the circulating air passage for introducing air into the circulating air passage. The predetermined position is at least one of the positions between the filter and the evaporator, and between the condenser and the blower in the circulating air passage.

[0034] Since corrosion current sensors are positioned in at least one of the locations within the circulating air passage—between the filter and the evaporator, and between the condenser and the blower—the corrosion current sensors can detect bubbles that enter the circulating air passage by flowing backward, and this can be used to suppress the progression of corrosion in the evaporator or condenser.

[0035] According to a thirteenth aspect of this disclosure, in a washer-dryer of any of the first to twelfth aspects, the washer-dryer has a communication unit that transmits information on corrosion current detected by a corrosion current sensor to another device. This allows the other device to use the corrosion current information to determine when the washer-dryer needs maintenance, thereby improving maintainability.

[0036] Hereinafter, exemplary embodiments of the washing machine and dryer according to this disclosure will be described with reference to the attached drawings. This disclosure is not limited to the specific configurations of the embodiments described below, but includes configurations based on similar technical ideas. (Embodiment 1) A washing machine and dryer according to Embodiment 1 of this disclosure will be described.

[0037] [1. Structure] [1-1. Overall Structure] Figure 1 is a schematic cross-sectional view showing a washing machine 1 according to Embodiment 1 of the present disclosure. Figure 2 is a schematic cross-sectional view of the inside of the circulating air passage 24, and Figure 3 is a schematic plan cross-sectional view of the inside of the circulating air passage 24. As shown in Figure 1, the washing machine 1 comprises a housing 2, a washing tub 3, a rotating tub 4, a drive unit 5, a water supply pipe 8, a drain valve 11, a control unit 12, and an operation display unit 16.

[0038] The housing 2 is a component that forms the exterior of the washing machine 1. The front of the housing 2 is provided with an opening 20 and a door 21 that can be opened and closed to cover the opening 20.

[0039] The washing tub 3 is a roughly cylindrical member located inside the housing 2 and has the function of holding washing water. The washing tub 3 may also be called a water tank. The washing tub 3 has a cylindrical portion 34 and a bottom portion 37 that closes one end of the cylindrical portion 34. The central axis V0 of the washing tub 3 passes through the center of the bottom portion 37. The central axis V0 is inclined with respect to the horizontal. The washing tub 3 is elastically supported by a damper 30 and a coil spring (not shown), and vibrations during washing and spinning are absorbed by the damper 30 and the coil spring. The washing tub 3 has an opening 31 facing the opening 20 of the housing 2, and is sealed and connected to the opening 20 of the housing 2 by a sealing member 32, such as a bellows. The washing tub 3 is further provided with an opening 33 for water passage and a drain port 35. The opening 33 is an opening connected to the water supply pipe 8, and the drain port 35 is an opening for draining the water from the washing tub 3 to the outside.

[0040] Furthermore, the horizontal direction along the central axis V0 is defined as the front-to-back direction M (Figure 1), and the horizontal direction perpendicular to the plane containing the central axis V0 is defined as the width direction K (Y-axis direction). The front-to-back direction M (X-axis direction) has a front side M1 toward the opening 31 and a rear side M2 ​​toward the bottom 37.

[0041] The rotating tub 4 is a roughly cylindrical member that is rotatable around a central axis V0 inside the washing tub 3 and contains the items to be processed 15 as laundry. The rotating tub 4 may also be called a drum. The rotating tub 4 has a number of through holes 40. The through holes 40 connect the rotating tub 4 and the washing tub 3, allowing the washing water to move between the rotating tub 4 and the washing tub 3. The rotating tub 4 also has openings 41 at positions facing the opening 20 of the housing 2 and the opening 31 of the washing tub 3.

[0042] The drive unit 5 is a component that rotates the rotating tank 4. The drive unit 5, for example, has a motor that rotates the rotating tank 4.

[0043] The water supply pipe 8 is a passage for carrying water from the water inlet 10, to which a water supply hose is connected, to the washing tub 3. The water supply pipe 8 is connected to the washing tub 3 via the water inlet 10, the water supply valve 9, and the liquid agent input section 13. In this specification, "liquid agent" refers to a liquid agent used to wash items to be treated 15 such as clothing, and includes detergents, fabric softeners, neutral detergents, etc.

[0044] The drain valve 11 is configured to be openable and closable, and when opened, it is a valve that drains the water stored in the washing tub 3 through the drain port 35 of the washing tub 3. The drain valve 11 is located at the bottom of the housing 2.

[0045] The control unit 12 controls the washing operation of the washing machine 1, including the washing, rinsing, and spinning processes, and the drying operation, including the drying process. The control unit 12 controls the components of the washing machine 1, such as the drive unit 5, the heat pump unit 6, the water supply valve 9, and the drain valve 11. The control unit 12 may, for example, include a memory (not shown) that stores a program and a processing circuit (not shown) corresponding to a processor such as a CPU, and the processor may function as these elements by executing the program.

[0046] The operation display unit 16 receives operation instructions from the user to the control unit 12, and the control unit 12 displays information regarding the settings and operating status to the user. The operation display unit 16 is, for example, a liquid crystal touch panel, but buttons as an operation unit and a liquid crystal panel as a display unit may be arranged separately. Furthermore, the operation display unit 16 is not limited to visual displays and may also include a notification unit that informs the user through auditory means such as a speaker emitting voice or alarm sounds, and tactile means such as touch.

[0047] [1-2.Circulation air path] The washing tub 3 is provided with an exhaust port 22 and an intake port 23, and a circulating air passage 24 is connected from the exhaust port 22 to the intake port 23. During the drying operation, the heat pump unit 6 dehumidifies and heats the air that flows from the washing tub 3 into the circulating air passage 24, and this air is returned to the washing tub 3. This allows the items to be processed 15 after the washing operation to be dried. In this embodiment, the exhaust port 22 is provided at the top of the washing tub 3 and the intake port 23 is provided at the bottom 37 of the washing tub 3, but it is not limited to this, and for example, they may be provided so that the airflow is in the opposite direction.

[0048] The circulating air passage 24 includes a filter 25, an air blower 26, a heat exchanger 7 of the heat pump unit 6, and a water sprayer 27. The heat exchanger 7 comprises an evaporator 45 and a condenser 46.

[0049] The filter 25 is installed upstream of the heat exchanger 7 in the circulating air passage 24 and is a component that removes dust and lint contained in the air flowing into the circulating air passage 24.

[0050] The air blower unit 26 is a component for drawing air from the washing tub 3 into the circulating air passage 24, and is composed of, for example, a fan and a motor.

[0051] The water spraying unit 27 is a component that sprays water onto the heat exchanger 7. This allows foam adhering to the heat exchanger 7 to be washed away. The water spraying unit 27 is, for example, a nozzle and is positioned opposite the evaporator 45 and the condenser 46, respectively.

[0052] Furthermore, the water spraying section 27 does not necessarily need to be provided for both the evaporator 45 and the condenser 46 of the heat exchanger 7. For example, if the configuration does not allow foam to enter the evaporator 45, then the water spraying section 27 for the evaporator 45 is unnecessary. However, the evaporator 45 may accumulate fine dust that cannot be captured by the filter 25. For this reason, it may be provided to wash away this accumulated fine dust, or it may be configured to wash away both foam and dust.

[0053] The heat pump unit 6 will be described with reference to Figures 4A and 4B. Figure 4A is a schematic diagram showing an example of the heat pump unit 6. Figure 4B is a schematic partial perspective view showing an example of the evaporator 45 and condenser 46. The heat pump unit 6 has a generally well-known configuration, in which the refrigerant piping 53 is connected in the order of the evaporator 45, compressor 51, condenser 46, and expansion mechanism 52. The refrigerant piping 53 has, for example, a hollow cylindrical shape. The compressor 51 circulates the refrigerant through the refrigerant piping 53.

[0054] The evaporator 45 and condenser 46 of the heat exchanger 7 are installed in the circulating air passage 24 and fixed by fixing members 49 (see Figure 3). The evaporator 45 dehumidifies the air by cooling the incoming air and condensing the water vapor contained in the air. The condenser 46 heats the incoming air. In the circulating air passage 24, the evaporator 45 is located on the upstream side, and the condenser 46 is located downstream of the evaporator 45. In addition, an air passage drain port 50 for discharging condensed water generated in the evaporator 45 and water sprayed from the water spraying unit 27 is formed on the bottom surface of the circulating air passage 24.

[0055] In this embodiment, the evaporator 45 is arranged at a slight incline, and the condenser 46 is arranged upright. The arrangement, including the inclination of the heat exchanger 7, can be arbitrarily determined by the layout of the circulating air passage 24 inside the washing machine 1.

[0056] The evaporator 45 comprises fins 48 and a zigzag-shaped heat exchanger piping 47. The fins 48 are made up of multiple thin metal plates that are tightly attached to the heat exchanger piping 47 and are arranged to efficiently exchange heat with the air passing between each metal plate. The heat exchanger piping 47 is generally a cylindrical pipe, but as shown in Figure 4B, it may also be a flat pipe with partitions inside and multiple microchannels (not shown). The fins 48 are not provided in the return section 47a that is bent to form the zigzag shape of the heat exchanger piping 47. The evaporator 45 exchanges heat to cool the air and vaporize the refrigerant. In the evaporator 45, the refrigerant that flows from the refrigerant piping 53 into the heat exchanger piping 47 flows through the heat exchanger piping 47 while exchanging heat with the air, and flows out to the refrigerant piping 53 toward the compressor 51.

[0057] The condenser 46 has a structure similar to that of the evaporator 45. The condenser 46 heats the air and exchanges heat to liquefy the refrigerant. In the condenser 46, the refrigerant that flows from the refrigerant piping 53 into the heat exchanger piping 47 exchanges heat with the air as it flows through the heat exchanger piping 47 and flows out into the refrigerant piping 53 towards the expansion mechanism 52.

[0058] The heat exchanger piping 47 of the evaporator 45 and condenser 46 can be made primarily of copper or primarily of aluminum. In particular, piping made primarily of aluminum is more susceptible to corrosion than piping made primarily of copper.

[0059] [1-3. Corrosion Current Sensor] The corrosion current sensor 61 simulates corrosion in the heat exchanger piping 47 and detects the corrosion current caused by the simulated corrosion. The corrosion current sensor 61 is, for example, an ACM (Atmospheric Corrosion Monitor) sensor. The corrosion current sensor 61 may continuously and quantitatively measure the corrosion current from the start of use of the heat pump unit 6. For example, the corrosion current sensor 61 measures the corrosion current every 0.1 seconds.

[0060] As shown in Figures 1 to 3, the corrosion current sensor 61 is positioned at a predetermined location, such as on the fins 48 of the evaporator 45 and condenser 46, or on the outer surface of the heat exchanger piping 47.

[0061] When the corrosion current sensor 61 is placed on the heat exchanger piping 47, the corrosion environment of the corrosion current sensor 61 can be matched to the corrosion environment of the heat exchanger piping 47. The corrosion current sensor 61 may be attached to the part of the heat exchanger piping 47 where corrosion is to be detected. The flexible corrosion current sensor 61 may be deformed to match the shape of the outer surface of the heat exchanger piping 47 and attached to the heat exchanger piping 47. For example, the corrosion current sensor 61 can be attached to the heat exchanger piping 47 by attaching it with an adhesive layer on the back of the corrosion current sensor 61, attaching it with adhesive, brazing, soldering, or spot welding. Alternatively, the corrosion current sensor 61 can be attached to the heat exchanger piping 47 by inserting it into a case attached to the heat exchanger piping 47.

[0062] Figures 5 and 6 are schematic diagrams of the corrosion current sensor 61 according to the embodiment. In particular, Figure 6 is a cross-sectional view of the corrosion current sensor 61 with a water film 67 attached. The corrosion current sensor 61 comprises a base material 62, an insulating layer 63, a cathode electrode 64, a conductor 65, and an insulating protective layer 66.

[0063] The base material 62 is formed from a conductive material. For example, the base material 62 is formed from the same material as the material that constitutes the heat exchanger piping 47. Therefore, if the heat exchanger piping 47 is made of a material mainly composed of aluminum, the base material 62 will also be mainly composed of aluminum. Similarly, if the heat exchanger piping 47 is made of a material mainly composed of copper, the base material 62 will also be mainly composed of copper. Thus, the corrosion of the heat exchanger piping 47 can be reproduced in the base material 62. As a result, the corrosion of the heat exchanger piping 47 can be accurately detected based on the corrosion of the base material 62 measured by the corrosion current sensor 61.

[0064] The base material 62 is formed in a plate shape. By reducing the thickness of the base material 62, the corrosion current sensor 61 can be easily deformed, and the shape of the corrosion current sensor 61 can be adjusted to the installation location of the corrosion current sensor 61. In addition, the thickness of the base material 62 and the thickness of the heat exchanger piping 47 may be approximately the same. For example, the thickness of the base material 62 is 0.8 times or more and 1.2 times or less the thickness of the heat exchanger piping 47. Preferably, the thickness of the base material 62 is 0.9 times or more and 1.1 times or less the thickness of the heat exchanger piping 47.

[0065] The insulating layer 63 is formed in a plate shape. The insulating layer 63 is laminated on one side of the substrate 62. On the other hand, the substrate 62 is exposed on the side after the insulating layer 63 has been laminated. The insulating layer 63 is an electrically insulating material. The material that forms the insulating layer 63 is, for example, a resin.

[0066] The cathode electrode 64 is laminated on the side of the insulating layer 63 opposite to the substrate 62. The cathode electrode 64 is made of a material that is conductive and has a surface potential nobler than that of the substrate 62. When the surface potential of the cathode electrode 64 is nobler than that of the substrate 62, the substrate 62 corrodes preferentially, so corrosion of the heat exchanger piping 47 can be detected using the corrosion current sensor 61.

[0067] The corrosion current sensor 61 is an ACM sensor in which, for example, the cathode electrode 64 is formed of copper, silver, or carbon, which has a surface potential nobler than the aluminum of the substrate 62 that serves as the anode electrode. Alternatively, the cathode electrode 64 is formed of silver or carbon, which has a surface potential nobler than the copper of the substrate 62 that serves as the anode electrode.

[0068] The corrosion current sensor 61 is provided with a conductor 65 between the base material 62, the cathode electrode 64, and the control unit 12, with the conductor 65 electrically connecting each of them. The conductor 65 is made of an electrically conductive material. For example, the conductor 65 is made of copper.

[0069] The insulating protective layer 66 is placed at the connection point between the conductor 65, the substrate 62, and the cathode electrode 64, and protects the connection point. The insulating protective layer 66 is formed of an electrically insulating material. For example, the insulating protective layer 66 is formed of resin.

[0070] The water film 67 is formed by bubbles that enter the circulating air passage 24 and comes into contact with a portion of the substrate 62 and a portion of the cathode electrode 64. Since water is electrically conductive, the formation of the water film 67 causes electrical conductivity between the substrate 62 and the cathode electrode 64. Because a potential difference exists between the substrate 62 and the cathode electrode 64, a corrosion current flows. The corrosion current flows from the substrate 62 through the conductor 65 of the external circuit and the control unit 12 toward the cathode electrode 64. At this time, the corrosion current is detected in the control unit 12.

[0071] The control unit 12 determines corrosion of the heat exchanger piping 47 based on changes in the corrosion current. More specifically, the control unit 12 determines corrosion of the heat exchanger piping 47 by determining whether the corrosion current detected by the corrosion current sensor 61 is above a predetermined threshold. For example, if the control unit 12 determines that the corrosion current is above a predetermined threshold, it determines that corrosion is occurring in the heat exchanger piping 47.

[0072] [2. Effect] [2-1. Airflow within the circulating air duct] Next, the airflow within the circulating air passage 24 will be explained with reference to Figures 1 to 3. During the drying process, air flowing from the washing tub 3 through the exhaust port 22 into the circulating air passage 24 passes through the filter 25, evaporator 45, and condenser 46 to reach the blower unit 26. The blower unit 26 pushes the incoming air further into the passage, causing the air in the circulating air passage 24 to flow out of the intake port 23 into the washing tub 3 and be circulated.

[0073] As shown in Figure 2, the moisture-laden air A1 flowing in from the washing tub 3 passes through the filter 25 along the circulation air passage 24, then through the evaporator 45 where it is dehumidified. The air A2 that has passed through the evaporator 45 is heated as it passes through the condenser 46. As a result, the high-temperature, low-humidity air A3 flows along the circulation air passage 24 towards the intake port 23 and the rotating tub 4, and then flows out into the washing tub 3.

[0074] The water condensed in the evaporator 45 from the high-humidity air falls to the bottom of the circulating air passage 24 by its own weight and flows along the wall to the air passage drain outlet 50. Thus, the direction in which air flows from the washing tub 3 through the exhaust port 22, filter 25, blower 26, evaporator 45, condenser 46, and intake port 23 back to the washing tub 3 is defined as the forward direction. Within this forward flow, the exhaust port 22 side is defined as the upstream side and the intake port 23 side as the downstream side. [2-2. Detection by corrosion current sensor]

[0075] Next, with reference to Figures 1 to 3, the placement of the corrosion current sensor 61 in the circulating air passage 24 and the detection of corrosion current will be described. The corrosion current sensor 61 is installed in the following predetermined location within the circulating air passage 24.

[0076] Detergent foam generated in the washing tub 3 may enter the circulating air passage 24 in the forward direction from the exhaust port 22 and reach the evaporator 45, or it may enter the circulating air passage 24 in the reverse direction from the intake port 23 and reach the condenser 46. This foam can accelerate corrosion of the evaporator 45 and condenser 46.

[0077] In Figures 1 to 3, the corrosion current sensor 61 is positioned in three locations: on the fin 48 on the lower upstream side of the evaporator 45, on the fin 48 on the lower downstream side of the condenser 46, and on the outer surface of the heat exchanger piping 47. However, it is not limited to these locations and can be positioned in other places as well.

[0078] First, to illustrate the location where the corrosion current sensor 61 is placed on the evaporator 45 side, it is located on the fins 48 exposed on the upstream side of the circulating air passage 24 in the evaporator 45, as shown in region AE1 in Figures 2 and 3. In this embodiment, since the fixing member 49 is provided on the upstream side, the return section 47a is not exposed. However, if the fixing member 49 is provided on the downstream side, the return section 47a will be exposed, and therefore region AE1 will also include the return section 47a. At these locations, when foam Ba1 comes from the upstream side of the evaporator 45 during the washing process, the foam Ba1 covers the corrosion current sensor 61, so the corrosion current sensor 61 can detect the corrosion current under the same conditions as the corrosion status of the evaporator 45.

[0079] Furthermore, the corrosion current sensor 61 may be placed on the wall surface near the upstream side of the circulating air passage 24, including the side and bottom surfaces, surrounding the evaporator 45, or it may be placed on the fixing member 49. For example, region AE2 in Figures 2 and 3 is such a location. At this location, detergent foam Ba1 entering the circulating air passage 24 in the forward direction is likely to adhere to the sensor, so the corrosion current sensor 61 can detect the corrosion current under the same conditions as the corrosion conditions of the corrosion-prone areas of the evaporator 45.

[0080] Thus, in the vicinity of the upstream side of the evaporator 45, such as regions AE1 and AE2 in Figures 2 and 3, the detergent foam Ba1 entering the circulating air passage 24 in the forward direction during the washing process is most likely to adhere to the evaporator 45 and its walls. Therefore, the corrosion current sensor 61 can detect corrosion current under the same conditions as the corrosion conditions of the corrosion-prone areas of the evaporator 45. Furthermore, even in the vicinity of the upstream side of the evaporator 45, the lower part is particularly preferable as an installation location for the corrosion current sensor 61 because the foam Ba1 reaches it more quickly there.

[0081] Next, an example of where the corrosion current sensor 61 is placed on the capacitor 46 side is shown in region AC1 in Figures 2 and 3, which is on the fin 48 exposed downstream of the circulating air passage 24 in the capacitor 46. In this embodiment, a fixing member 49 is provided on the upstream side, and the bent return portion 47a of the heat exchanger piping 47 is exposed in region AC2. Therefore, region AC1 also includes the return portion 47a. At these locations, when foam Ba2 comes from the downstream side of the capacitor 46 during the washing process, the foam Ba2 covers the corrosion current sensor 61, so the corrosion current sensor 61 can detect the corrosion current under the same conditions as the corrosion condition of the capacitor 46.

[0082] Furthermore, a corrosion current sensor 61 may be placed on the wall surface of the circulating air passage 24, including the sides and bottom, surrounding the capacitor 46, near the downstream side. For example, region AC2 in Figures 2 and 3 is such a location. At this location, detergent foam Ba2 entering the circulating air passage 24 in the reverse direction is likely to adhere, so the corrosion current sensor 61 can detect the corrosion current under the same conditions as the corrosion conditions of the easily corroded parts of the capacitor 46.

[0083] Thus, for example, in the vicinity of the downstream side of the capacitor 46, such as regions AC1 and AC2 in Figures 2 and 3, the detergent foam Ba2 that enters the circulating air passage 24 in the reverse direction during the washing process is most likely to adhere to the capacitor 46 and its walls. Therefore, the corrosion current sensor 61 can detect corrosion current under the same conditions as the corrosion conditions of the areas of the capacitor 46 that are prone to corrosion. Furthermore, even in the vicinity of the downstream side of the capacitor 46, the lower part is particularly preferable as an installation location for the corrosion current sensor 61 because the foam Ba2 reaches there more quickly.

[0084] The corrosion current sensor 61 may be configured as a foam sensor that detects abnormal foam formation. When configured as a foam sensor, the control unit 12 can interrupt the washing operation of the washing machine 1 and perform actions to reduce abnormal foam in response to foam detection by the corrosion current sensor 61. It can also notify the user of abnormal foam formation.

[0085] Furthermore, the installation of the corrosion current sensor 61 does not prevent the installation of other foam sensors. For example, a first foam sensor that detects small amounts of foam abnormalities may be installed in the circulating air passage 24 on the washing tub 3 side of the filter 25 or the blower unit 26, and the corrosion current sensor 61 may be used as a second foam sensor that detects large amounts of foam abnormalities.

[0086] [2-3. Watering Operation] Next, the watering operation performed by the watering unit 27 will be described with reference to Figures 1 to 3. The control unit 12 receives the corrosion current value detected by the corrosion current sensor 61, and when it determines that the corrosion current value is above a predetermined value, it performs a watering operation, spraying water from the watering unit 27 towards the evaporator 45 and condenser 46. This washes away the foam adhering to the evaporator 45 and condenser 46. Alternatively, instead of automatically performing the watering operation, the control unit 12 may display a watering operation guide to the user on the operation display unit 16 and wait for user instructions.

[0087] The control unit 12 may activate only the water spraying unit 27 that sprays water on the evaporator 45 if the corrosion current value detected by the corrosion current sensor 61 located near the evaporator 45 is above a predetermined value. Alternatively, the control unit 12 may activate only the water spraying unit 27 that sprays water on the capacitor 46 if the corrosion current value detected by the corrosion current sensor 61 located near the capacitor 46 is above a predetermined value. In this way, the control unit 12 may individually control the operation of the water spraying unit 27 when the current value of the corresponding corrosion current sensor 61 is above a predetermined value, or it may activate multiple water spraying units 27 simultaneously to spray water on both the evaporator 45 and the capacitor 46 if the corrosion current value detected by even one of the multiple corrosion current sensors 61 is above a predetermined value.

[0088] [2-4. Corrosion Test] Next, referring to Figures 7 to 9, we will explain the corrosion current detected by the corrosion current sensor 61 in corrosion tests conducted on the corrosion current sensor 61 for each type of liquid agent introduced into the washing tub 3. The following shows the monitoring results of corrosion current in environments where temperature and humidity change. In the following explanation, "humidity" refers to relative humidity. Relative humidity is correlated with the thickness of the water film 67 formed on the substrate 62 of the corrosion current sensor 61. Figure 7 is a graph showing the temperature and humidity change profile. Figure 8 is a graph showing the change in corrosion current for each liquid agent under the conditions of Figure 7. Figure 9 is a graph showing the relative humidity dependence for each liquid agent.

[0089] In Figure 7, line 69 shows the temperature profile in the constant temperature and humidity chamber and corresponds to the vertical axis on the left. Line 70 shows the humidity profile in the constant temperature and humidity chamber and corresponds to the vertical axis on the right. The horizontal axis is common to all lines and represents the test time.

[0090] As shown in Figure 7, a liquid agent is dropped onto the corrosion current sensor 61, and the humidity is gradually increased while maintaining the temperature at 30°C until it reaches 90%RH or higher. The temperature remains the same, but the humidity is lowered to around 30%RH and maintained for about 2 hours, allowing the moisture on the surface of the substrate 62 to completely evaporate and reset to its initial state. Next, the temperature is raised to 40°C, and the humidity is again gradually increased until it reaches 90%RH or higher. The temperature remains the same, allowing the dropped liquid agent to completely dry and the moisture to evaporate. Next, the temperature is raised to 50°C, and the humidity is again gradually increased until it reaches 90%RH or higher. The temperature remains the same, allowing the dropped liquid agent to completely dry and the moisture to evaporate. After that, the temperature and humidity are left at natural conditions.

[0091] As shown in Figure 8, in this study, the corrosion current values ​​were monitored for four liquid agents. Detergent 71 was a commercially available liquid detergent at a concentration of 0.25 wt%, fabric softener 72 was a commercially available liquid fabric softener at a concentration of 0.13 wt%, disinfectant 73 was a commercially available liquid disinfectant at a concentration of 0.25 wt%, and mixed agent 74 was an aqueous solution containing all three of these. The disinfectant is a liquid agent for disinfecting clothing, and its main component is, for example, chlorooxylenol (4-chloro-3,5-dimethylphenol).

[0092] The changes in corrosion current shown in Figure 8 were detected as follows. First, 70 μL of each liquid agent was dropped onto the substrate 62 of the corrosion current sensor 61 and allowed to dry completely. After drying, the residue of the liquid agent remained on the substrate 62. In this state, the corrosion current values ​​detected by the corrosion current sensor 61 were monitored in a constant temperature and humidity chamber while controlling the temperature and humidity environment as shown in Figure 9.

[0093] In Figure 8, the vertical axis represents the magnitude of the corrosion current, and the horizontal axis represents the test time. As shown in Figure 8, the corrosion current values ​​tend to be higher for detergent 71 and the mixture containing detergent 71 74 compared to the fabric softener 72 and the disinfectant 73. Between 30°C and 40°C, and between 40°C and 50°C, when the humidity is increased after drying, the residue remaining on the surface of the substrate 62 deliquesces and spreads wet on the substrate 62.

[0094] Furthermore, the corrosion current value increases as humidity increases. Figure 9 is a graph that makes this easier to understand. In Figure 9, the horizontal axis represents humidity and the vertical axis represents the corrosion current value. As humidity increases, the corrosion current values ​​of detergent 71 (indicated by the × mark) and mixture 74 (indicated by the ○ mark) increase significantly compared to fabric softener 72 (indicated by the △ mark) and disinfectant 73 (indicated by the ■ mark).

[0095] Thus, it has been newly discovered that detergents and humidity are factors that accelerate corrosion, and that the value of the corrosion current increases when these two factors are combined. The detergent factor will be explained in more detail below.

[0096] Furthermore, information on corrosion has been previously published in the paper "Recent Advances in Atmospheric Corrosion Evaluation Methods" by Masashi Shinohara (Surface Science Vol.36. No.1, pp.4-11, 2015). Figure 10 is a graph from this paper, showing the change in corrosion rate with respect to the thickness of the water film. The horizontal axis represents the thickness of the water film, and the vertical axis represents the corrosion current. Region I represents a state where several molecular layers of water are adsorbed, region II represents a corrosion state due to the adsorption of 10 to 100 molecular layers of water, and regions III and IV represent states where the liquid film is even thicker.

[0097] In region II, the liquid film begins to function as an electrolyte solution, making corrosion more likely to proceed through electrochemical reactions, and the corrosion rate increases rapidly. Also, when oxygen from the air dissolves in the water film, the dissolved oxygen is immediately supplied to the metal surface, so the corrosion current value increases. In region III, the supply of dissolved oxygen to the metal surface is delayed, so the corrosion rate decreases.

[0098] In the corrosion current sensor 61, in a high-humidity environment where no detergent is present, the water film on the substrate 62 becomes sufficiently thick, and the corrosion current value stabilizes at the state where the water film thickness is 1 mm. In other words, this state is state D1, near the boundary between regions III and IV, and is a normal wet state. The inventors of this application hypothesized that when a surfactant such as detergent is present in the water film 67, the water film 67 on the substrate 62 becomes thinner due to the influence of the surfactant, and that the state transitions from state D1 to state D2, near the boundary between regions II and III, and that the corrosion current value increases as the water film 67 becomes thinner.

[0099] Next, the behavior of corrosion current during drying operation in relation to humidity will be explained with reference to Figures 11 to 14. Figures 11 and 12 are graphs showing the case when detergent 71 is sprayed onto the evaporator 45 and condenser 46 located in the washing machine 1, but drying operation is not performed. Corrosion current sensors 61 are located on both the evaporator 45 and condenser 46. Figure 11 is a graph showing the temperature change profile inside the heat pump unit 6. Figure 12 is a graph showing the time course of corrosion current detected by corrosion current sensors 61 located on both the evaporator 45 and condenser 46. Figures 13 and 14 are graphs showing the case when detergent 71 is sprayed onto the evaporator 45 and condenser 46 located in the washing machine 1, and drying operation is performed. Figure 13 is a graph showing the temperature and humidity profiles inside the heat pump unit 6. Figure 14 is a graph showing the time course of corrosion current detected by corrosion current sensors 61 located on both the evaporator 45 and condenser 46.

[0100] As shown in Figure 11, when the drying operation is not performed, the temperature T1 inside the heat pump unit 6 is approximately the same as the temperature of the room where the washing machine / dryer 1 is installed, and remains around 22°C.

[0101] As shown in Figure 12, when no drying operation is performed, the corrosion current Ct1 detected by the corrosion current sensor 61 located on the evaporator 45 increases over time, and the current value gradually rises. On the other hand, the corrosion current Ct2 detected by the corrosion current sensor 61 located on the capacitor 46 decreases over time and eventually stabilizes at a certain current value a. The difference in the initial corrosion current between the evaporator 45 and the capacitor 46 may be due to differences such as differences in their installation angles, but the general trend can be easily understood by focusing on the changes after 4 hours.

[0102] Next, we will explain the trend of corrosion current when a drying operation is performed. As shown in Figure 13, detergent 71 was sprayed onto the evaporator 45 and condenser 46 located in the washing machine 1, and then a drying operation was performed for 2 hours. The origin of the horizontal axis in Figure 13 is the start of the drying operation. During the drying operation, the temperature T3 of the condenser 46 is higher than the temperature T2 of the evaporator 45, but after the drying operation, as time passes, the temperatures of both become equal and are the same as room temperature. The humidity Hy decreases temporarily due to the drying operation and then rises again.

[0103] As shown in Figure 14, the corrosion current Ct3 detected by the corrosion current sensor 61 located in the evaporator 45 and the corrosion current Ct4 detected by the corrosion current sensor 61 located in the capacitor 46 show significant time fluctuations immediately after the start of the drying operation. Subsequently, after the drying operation is performed for 2 hours, and then after another 2 hours have passed, the trends in each value from the starting point to 4 hours later show generally stable trends. After 4 hours from the starting point, both the corrosion currents Ct3 and Ct4 are much smaller than a certain current value a, and are significantly lower than the corrosion current values ​​when the drying operation is not performed. Thus, by performing a drying operation and temporarily reducing the humidity, the generation of corrosion current can be significantly suppressed.

[0104] Next, with reference to Figure 15, we will compare and explain the amount of corrosion estimated from the corrosion current sensor 61 under each condition. Figure 15 is a graph showing the time course of the amount of corrosion under each condition. The horizontal axis of Figure 15 represents the test time, and the vertical axis represents the amount of corrosion. Since the amount of corrosion is proportional to the amount of charge, it can be estimated from the amount of charge.

[0105] In Figure 15, the plots marked with ● represent the detected values ​​under the condition of no drying operation after detergent spraying, and line 81 is a graph showing the time course of the corrosion amount estimated from the corrosion current sensor 61 under this condition. The plots marked with ▲ represent the detected values ​​under the condition of drying operation after detergent spraying, and line 82 is a graph showing the time course of the corrosion amount estimated from the corrosion current sensor 61 under this condition. The plots marked with □ represent the detected values ​​under the condition of no detergent spraying and no drying operation, and line 83 is a graph showing the time course of the corrosion amount estimated from the corrosion current sensor 61 under this condition.

[0106] Comparing these graphs, it can be seen that the presence of detergent and the absence of a drying cycle are conditions in which corrosion progresses much more rapidly than other conditions, and that corrosion progresses considerably when detergent is present and humidity is high. Conversely, if detergent does not adhere to the corrosion current sensor 61, or if a drying cycle is performed, corrosion can be significantly suppressed.

[0107] Therefore, if detergent can be removed from the evaporator 45 and condenser 46, or if humidity can be reduced, corrosion of the heat exchanger piping 47 can be significantly suppressed.

[0108] [2-5. Determination of corrosion in heat exchanger piping] The control unit 12 stores the accumulated charge amount calculated from the corrosion current detected by the corrosion current sensor 61 since the start of use of the washing machine 1. If it recognizes that the accumulated charge amount has reached a value that may cause a hole to penetrate the evaporator 45, condenser 46, or heat exchanger piping 47, it can prompt the user to replace the heat pump unit 6 by displaying a message on the operation display unit 16 indicating that the heat pump unit 6 should be replaced.

[0109] In this embodiment, in order to reduce humidity after operation of the washing machine 1, the control unit 12 performs a drying operation even if not instructed by the user, if the corrosion current value detected by the corrosion current sensor 61 is above a predetermined threshold during the washing process. The drying operation may be performed for a predetermined time, or it may be performed until the corrosion current value detected by the corrosion current sensor 61 falls below a predetermined threshold. Note that this drying operation differs from a drying process in which the rotating tub 4 is rotated to agitate the workpiece 15, and may be an airflow drying operation in which the drying of the workpiece 15 in the washing tub 3 is suppressed without rotating the rotating tub 4.

[0110] Furthermore, in order to remove detergent foam from the evaporator 45 and condenser 46 of the washing machine 1, the water spraying unit 27 sprays water onto the evaporator 45 and condenser 46 after the washing cycle. The water spraying unit 27 is, for example, a nozzle connected to a hose that communicates with the water supply pipe 8 via a valve (not shown). The control unit 12 controls the water spraying from the water spraying unit 27 by controlling the opening and closing of the valve.

[0111] The operation display unit 16 displays the corrosion determination result of the evaporator 45, condenser 46, or heat exchanger piping 47, as determined by the control unit 12. The corrosion determination result is, for example, the degree of corrosion progression. The operation display unit 16 includes a liquid crystal panel and a control circuit that controls the liquid crystal panel, and displays information on the liquid crystal panel by receiving a signal from the control unit 12. For example, when the control unit 12 determines that the corrosion progression is quite advanced, it sends a signal to the control circuit of the operation display unit 16. When the control circuit receives a signal from the control unit 12, it displays information indicating the degree of corrosion progression or the high probability of refrigerant leakage due to corrosion. Information may also be provided by LEDs in addition to the liquid crystal panel. In this way, the operation display unit 16 displays the corrosion determination result of the evaporator 45, condenser 46, or heat exchanger piping 47, as determined by the control unit 12. Furthermore, if the control unit 12 determines that corrosion has progressed considerably, the operation display unit 16 may output audio information indicating this, sound an alarm such as a buzzer, or vibrate the operation display unit 16 in order to more strongly inform the user of the risk of refrigerant leakage.

[0112] This allows the user of the washing machine / dryer 1 to see the results of the corrosion assessment of the heat exchanger piping 47 of the evaporator 45 and condenser 46. By informing and prompting the user of the need to replace or repair the heat exchanger piping 47, appropriate measures can be taken before a hole penetrates the heat exchanger piping 47 of the evaporator 45 and condenser 46 and causes refrigerant leakage. These notifications do not necessarily have to directly inform the user of the corrosion assessment results; for example, they may simply serve as an error message prompting a maintenance request.

[0113] Furthermore, the display of the corrosion detection result by the operation display unit 16 may also provide notification regarding the abnormal occurrence of foam during normal washing operations. Specifically, for example, if the corrosion current sensor 61 is also configured as a foam sensor, the operation display unit 16 may display that an abnormal occurrence of foam has been detected, that water will be sprayed onto the heat exchanger in response to this detection, and that a drying operation will be performed in response to this detection, thereby informing the user of the operating status.

[0114] The operation display unit 16 may be a display separate from the washing machine / dryer 1. If the operation display unit 16 is separate from the washing machine / dryer 1, the washing machine / dryer 1 and the operation display unit 16 may be equipped with a communication unit. The communication unit includes a circuit that communicates with the operation display unit 16 in accordance with a predetermined communication standard (e.g., LAN, Wi-Fi®, Bluetooth®). For example, the display of a smartphone may function as the operation display unit 16. The communication unit of the washing machine / dryer 1 and the smartphone may communicate, and the corrosion judgment result may be displayed on the smartphone. For example, an application compatible with the washing machine / dryer 1 may be installed on the smartphone, and the corrosion judgment result may be displayed on the smartphone by this application.

[0115] Furthermore, the operation display unit 16 may display the progression of corrosion in three stages. For example, the operation display unit 16 may display the state before corrosion occurred, the state immediately after corrosion occurred, or the state one month or more after corrosion occurred.

[0116] [3. Effects, etc.] The washing and drying machine 1 according to this embodiment can achieve the following effects.

[0117] As described above, the washing machine 1 of this embodiment comprises a washing tub 3, a heat pump unit 6, a circulating air passage 24, a control unit 12, and a corrosion current sensor 61. The washing tub 3 is elastically supported within the housing 2, and the heat pump unit 6 has a heat exchanger 7 including an evaporator 45 and a condenser 46, which blows hot air into the washing tub 3. The circulating air passage 24 is connected to the heat exchanger 7 of the heat pump unit 6 and the washing tub 3. The control unit 12 controls the washing operation, which includes a washing process, a rinsing process, and a spin-drying process, and the drying operation, which includes a drying process. The corrosion current sensor 61 is positioned on the heat exchanger 7, or in the vicinity of the heat exchanger 7 within the circulating air passage 24, at a predetermined position where detergent foam generated in the washing tub 3 and entering the circulating air passage 24 can adhere to it.

[0118] The corrosion current sensor 61 is positioned at a predetermined location on the heat exchanger 7, or at a predetermined location within the circulating air passage 24 near the heat exchanger 7, where detergent foam that has entered the circulating air passage 24 can adhere to it, thus enabling detection of foam intrusion into the circulating air passage 24. Furthermore, the corrosion status of the evaporator 45 and condenser 46 can be detected from the detection results of the corrosion current sensor 61, and this can be applied to a system for preventing shortened lifespan and predicting failures of the evaporator 45 and condenser 46. In addition, since the corrosion status can be estimated with high accuracy, it is possible to use aluminum, which is inexpensive but prone to corrosion, as the material for the evaporator 45 and condenser 46. Moreover, while miniaturizing the washing tub 3 makes it easier for foam to enter the circulating air passage, the intrusion of foam can be detected, and by addressing corrosion caused by foam, the washing tub 3 can be miniaturized.

[0119] Furthermore, the evaporator 45 and condenser 46 are equipped with heat exchanger piping 47 through which the refrigerant flows, and the predetermined position is the exposed surface of the heat exchanger piping 47 that is exposed to the circulating air passage 24.

[0120] If an abnormal amount of detergent foam is generated during the washing process, the foam may enter the circulating air passage 24 and reach either the upstream end of the evaporator 45 or the downstream end of the condenser 46, even if the fan is not operating. In this case, since the corrosion current sensor 61 is positioned on the exposed surface of the heat exchanger piping 47, which is a metal pipe that is prone to corrosion, among the evaporator 45 and condenser 46, the corrosion current can be monitored at a location where corrosion is likely to progress.

[0121] Furthermore, the evaporator 45 and condenser 46 each have fins 48 that come into contact with the air flowing along the circulating air passage 24, and the predetermined position is the exposed surface of the fins 48. As a result, the corrosion current sensor 61 is positioned on the exposed surface of the fins 48 of the evaporator 45 and condenser 46, so that it is possible to accurately detect when bubbles reach the evaporator 45 and condenser 46.

[0122] Furthermore, the predetermined location where the corrosion current sensor 61 is placed is either the wall surface of the circulating air passage 24 near the upstream side of the evaporator 45, or the wall surface of the circulating air passage 24 near the downstream side of the condenser 46. As a result, bubbles that enter the circulating air passage along the wall surface of the circulating air passage 24 are accurately detected by the corrosion current sensor 61 placed on the wall surface of the circulating air passage 24 near the upstream side of the evaporator 45, or the wall surface of the circulating air passage 24 near the downstream side of the condenser 46.

[0123] Furthermore, the corrosion current sensor 61 is configured as a foam sensor that detects abnormal foam formation. When the corrosion current sensor 61 is configured as a foam sensor, the control unit 12 can interrupt the washing operation of the washing machine 1 and perform actions to reduce abnormal foam in response to foam detection by the corrosion current sensor 61. It can also notify the user of abnormal foam formation.

[0124] Furthermore, the corrosion current sensor 61 includes an ACM sensor. Since the cathode electrode of the ACM sensor is made of a material with a more noble potential than the anode electrode, the progression of corrosion can be directly and quantitatively evaluated by analyzing the output of the ACM sensor.

[0125] Furthermore, if the user has not set a drying operation after the washing cycle, and the corrosion current sensor 61 detects a corrosion current exceeding a predetermined value during the washing cycle, the control unit 12 will perform an airflow drying operation that suppresses drying inside the washing tub 3 after the washing cycle is completed. Airflow drying is a drying operation that the control unit 12 performs automatically even if the user does not intend to dry the clothes.

[0126] If the corrosion current sensor 61 detects a corrosion current exceeding a predetermined value, it is assumed that foam has reached the evaporator 45 and condenser 46. Therefore, even if drying operation is not set, the progression of corrosion can be suppressed by drying the evaporator 45 and condenser 46 with an airflow drying operation after the washing cycle is completed. Furthermore, since the drying operation is performed automatically, there is no need for the user to perform any extra operations. In addition, since the airflow drying operation is a drying operation that suppresses drying inside the washing tub 3, power consumption can be reduced.

[0127] Furthermore, the washing and drying machine 1 is equipped with a water spraying unit 27 that sprays water onto the heat exchanger 7, and the control unit 12 includes control of the water spraying operation that sprays water from the water spraying unit 27. When the corrosion current sensor 61 detects a corrosion current of a predetermined value or higher, the control unit 12 performs the water spraying operation that sprays water from the water spraying unit 27.

[0128] When the corrosion current sensor 61 detects a corrosion current exceeding a predetermined value, it is assumed that foam has reached the evaporator 45 and condenser 46. By spraying water from the water spraying unit 27 towards the heat exchanger 7, the foam adhering to the evaporator 45 and condenser 46 can be washed away and removed, thereby suppressing the progression of corrosion of the evaporator 45 and condenser 46.

[0129] Furthermore, the control unit 12 performs a water spraying operation after the washing cycle is completed. As a result, the water spraying operation is automatically performed after the washing cycle is completed, and water is sprayed onto the heat exchanger 7 to wash away the foam, thereby suppressing the progression of corrosion of the evaporator 45 and condenser 46.

[0130] Furthermore, if the user has not set a drying operation after the washing cycle, the control unit 12 performs an airflow drying operation that suppresses drying inside the washing tub 3 after the water spraying operation. Even if the user has not set a drying process, the water spraying operation washes away the foam from the heat exchanger and the airflow drying operation is performed automatically, which further suppresses the progression of corrosion of the evaporator 45 and condenser 46. Moreover, since the airflow drying operation is a drying operation that suppresses drying inside the washing tub 3, power consumption can be reduced.

[0131] Furthermore, the washing and drying machine 1 is equipped with a water spraying unit 27 that sprays water onto the heat exchanger 7 and an operation display unit 16 that serves as a notification unit to transmit information to the user. The control unit 12 includes control of the water spraying operation that causes water to be sprayed from the water spraying unit 27, and when the corrosion current sensor 61 detects a corrosion current exceeding a predetermined value, the operation display unit 16 notifies the user to perform a drying operation or a water spraying operation.

[0132] This allows for the suppression of corrosion progression in the evaporator 45 and condenser 46 by prompting the user to perform drying or watering operations, even if these operations are not performed automatically.

[0133] Furthermore, the washing and drying machine 1 includes a filter 25 positioned upstream of the evaporator 45 in the circulating air passage 24, and a blower 26 positioned downstream of the condenser 46 in the circulating air passage 24 to introduce air into the circulating air passage 24. The predetermined position is at least one of the positions between the filter 25 and the evaporator 45, and between the condenser 46 and the blower 26 within the circulating air passage 24. This allows the corrosion current sensor 61 to detect bubbles entering the circulating air passage 24, which can be used to suppress the progression of corrosion in the evaporator 45 or the condenser 46.

[0134] (Embodiment 2) A washing and drying system 90 according to Embodiment 2 of this disclosure will now be described. In Embodiment 2, the differences from Embodiment 1 will be mainly described, and in Embodiment 2, components that are the same as or equivalent to those in Embodiment 1 will be denoted by the same reference numerals. In addition, in the description of Embodiment 2, points that overlap with Embodiment 1 will be omitted.

[0135] [1. Structure] Figure 16 is a block diagram of the washing and drying system 90 of Embodiment 2 according to the present disclosure. In Embodiment 2, the washing and drying machine 1A is the same as the washing and drying machine 1 of Embodiment 1 unless otherwise specified.

[0136] Embodiment 2 differs from Embodiment 1 in that the washing and drying machine 1A is a washing and drying system 90 that transmits information about corrosion current to an external device, the processing device 91.

[0137] As shown in Figure 16, the washing and drying system 90 comprises a washing and drying machine 1A and a processing unit 91.

[0138] The washing and drying machine 1A comprises a heat pump unit 6 having an evaporator 45, a condenser 46, and heat exchanger piping 47, a corrosion current sensor 61, a control unit 12, and a first communication unit 28. The control unit 12 has a storage unit that stores information on the corrosion current detected by the corrosion current sensor 61. The storage unit may be, for example, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, DVD or other optical disc storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device.

[0139] The first communication unit 28 transmits information regarding corrosion current stored in the memory unit of the control unit 12 via the network 94. The first communication unit 28 includes a circuit that transmits to the second communication unit 93 of the processing unit 91 in accordance with a predetermined communication standard (e.g., LAN, Wi-Fi®, Bluetooth®).

[0140] The processing unit 91 comprises a processing unit 92 and a second communication unit 93. The processing unit 92 is, for example, a computer, and the processing unit 91 is, for example, a server or a cloud.

[0141] The second communication unit 93 receives corrosion current information transmitted by the first communication unit 28 via the network 94. The second communication unit 93 includes a circuit that receives from the first communication unit 28 of the washing machine 1A in accordance with a predetermined communication standard (e.g., LAN, Wi-Fi®, Bluetooth®).

[0142] The processing unit 92 determines whether or not corrosion has occurred based on the corrosion current information received by the second communication unit 93.

[0143] [2. Effect] In the washing machine 1A, the corrosion current sensor 61 detects the corrosion current and stores the corrosion current information in the memory unit of the control unit 12. The first communication unit 28 transmits the corrosion current information stored in the memory unit to the second communication unit 93. The processing unit 91 receives the corrosion current information from the second communication unit 93. Based on the corrosion current information received from the second communication unit 93, the processing unit 92 determines the degree of corrosion progression in the heat exchanger piping 47 of the washing machine 1A.

[0144] This improves the accuracy of corrosion detection in the washing machine 1A and allows information on the corrosion current detected by the corrosion current sensor 61 to be transmitted from the washing machine 1A to another device. Specifically, information on the corrosion current detected by the corrosion current sensor 61 can be transmitted from the washing machine 1A to an independent processing unit 91. For example, if the seller has the processing unit 91, they can provide maintenance services based on the corrosion determination by the control unit 12. Therefore, it is possible to suppress the occurrence of malfunctions in the washing machine 1A, improve the efficiency of maintenance services, and improve user satisfaction.

[0145] The processing unit 91 may also receive information on corrosion currents from multiple washing and drying machines 1A, and may update the criteria for determining the degree of corrosion based on this information.

[0146] [3. Effects, etc.] The washing machine 1A of Embodiment 2 has a first communication unit 28 that transmits information on the corrosion current detected by the corrosion current sensor 61 to another device. As a result, the other device can use the corrosion current information to suppress the occurrence of malfunctions in the washing machine 1A, improve the efficiency of maintenance services, and increase user satisfaction.

[0147] While this disclosure is adequately described in relation to preferred embodiments with reference to the accompanying drawings, various modifications and alterations will be obvious to those skilled in the art. Such modifications and alterations should be understood to be included within the scope of the invention as defined by the appended claims. [Industrial applicability]

[0148] The washer-dryer of this disclosure is useful as a household washer-dryer, a commercial washer-dryer, or any type of washer-dryer (e.g., a household drum-type washer-dryer) equipped with a heat pump unit, as it can detect the intrusion of detergent foam into the circulating air passage and detect the corrosion current of the heat exchanger. [Explanation of Symbols]

[0149] 1. 1A Washer-Dryer 2 cabinets 3. Washing tub 4 Rotating tank 5 Drive Unit 6. Heat pump unit 8 Water pipe 9. Water supply valve 10 Water inlet 11 Drain valve 12 Control Unit 13. Liquid dispensing section 15. Items to be processed 16 Operation display section 20 aperture 21 Doors 22 Exhaust vents 23 Air intake 24 Circulating air duct 25 Filters 26 Air blower 27 Sprinkler section 28. First Communications Department 30 dampers 31 Aperture 32 sealing member 33 Aperture 34 Cylinder part 35 Drain 36 Drain pipe 37 Bottom 40 Through holes 41 Aperture 45 Evaporator 45a top side 45b Bottom side 46 Capacitors 46a Top side 46b Bottom surface 47 Heat exchanger piping 47a Return section 48 fins 49 Fixing member 50 Air channel drain 51 Compressor 52 Expansion Mechanism 53 Refrigerant piping 54 Airway drainage pipe 61 Corrosion Current Sensor 62 Base material 63 Insulating layer 64 Cathode electrodes 65 Conductor 66 Insulating protective layer 67 Water film Lines 69 and 70 71 Detergent 72 Fabric softener 73. Disinfectants 74 Mixture 90 Washing and Drying System 91 Processing Unit 92 Processing Unit A1, A2, A3 Air AC1, AC2, AC3 area AE1, AE2, AE3 area Ba1, Ba2 foam D1, D2 status Ct1, Ct2 corrosion current Hy Humidity K Width direction M Anteroposterior direction

Claims

1. A washing tub elastically supported inside the casing, A heat pump unit having a heat exchanger including an evaporator and a condenser, which blows hot air into the washing tub, A circulating air passage connected to the heat exchanger and the washing tub of the heat pump unit, A control unit that controls a washing operation including a washing process, a rinsing process, and a spin-drying process, and a drying operation including a drying process, The heat exchanger, or a corrosion current sensor positioned in the vicinity of the heat exchanger within the circulating air passage, at a predetermined location where detergent foam generated in the washing tub and entering the circulating air passage can adhere, comprises: Washer dryer.

2. The heat exchanger is equipped with heat exchanger piping through which the refrigerant flows. The predetermined position is the exposed surface of the heat exchanger piping that is exposed to the circulating air passage. The washing and drying machine according to claim 1.

3. The heat exchanger is equipped with fins that come into contact with the air flowing along the circulating air passage, The predetermined position is the exposed surface of the fin. The washing and drying machine according to claim 1.

4. The predetermined location is the wall surface of the circulating air passage near the upstream side of the evaporator, or the wall surface of the circulating air passage near the downstream side of the capacitor. The washing and drying machine according to claim 1.

5. The corrosion current sensor is configured as a bubble sensor that detects abnormal bubble formation. The washing and drying machine according to claim 1.

6. The corrosion current sensor includes an ACM (Atmospheric Corrosion Monitor) sensor. A washing machine and dryer according to any one of claims 1 to 5.

7. If the user has not set the drying operation after the washing operation, and the corrosion current sensor detects a corrosion current exceeding a predetermined value during the washing operation, the control unit shall perform an airflow drying operation that suppresses drying inside the washing tub after the washing operation is completed. The washing and drying machine according to claim 1.

8. The heat exchanger is equipped with a water spraying unit, The control unit includes control of the watering operation that causes water to be sprayed from the watering unit. When the corrosion current sensor detects a corrosion current exceeding a predetermined value, the control unit performs the water spraying operation. The washing and drying machine according to claim 1.

9. The control unit performs the watering operation after the washing operation is completed. The washing and drying machine according to claim 8.

10. If the user has not set the drying operation after the washing operation, the control unit will perform an airflow drying operation that suppresses drying inside the washing tub after the water spraying operation. The washing and drying machine according to claim 8.

11. A water spraying unit for spraying water onto the heat exchanger, It includes a notification unit that transmits information to the user, The control unit includes control of the watering operation that causes water to be sprayed from the watering unit. If the corrosion current sensor detects a corrosion current exceeding a predetermined value, the notification unit will provide guidance for the drying operation or the watering operation. The washing and drying machine according to claim 1.

12. A filter located upstream of the evaporator in the aforementioned circulating air passage, The aforementioned circulating air passage includes a blower unit positioned downstream of the capacitor, which allows air to flow into the circulating air passage. The predetermined position is at least one of the positions within the circulating air passage between the filter and the evaporator, and between the condenser and the air blower. The washing and drying machine according to claim 4.

13. The device has a communication unit that transmits information about the corrosion current detected by the corrosion current sensor to another device. The washing and drying machine according to claim 1.

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