Clothes dryer

Abstract

To provide a highly safe clothes dryer that can reduce ignition proclivity even if a flammable refrigerant leaks out.SOLUTION: In a clothes dryer according to the present invention, an evaporator 31 and a condenser 32 constituting a heat pump 35 have joint portions 31a3, 32a3 in which one end of a straight portion 31a1 and a first folded portion 31a2 are joined by brazing and one end of a straight portion 32a1 and a first folded portion 32a2 are joined by brazing among the refrigerant pipes through which the refrigerant flows, wherein the joint portions are arranged in a ventilation path 50 provided outside a circulation air passage 20, and the straight portions 31a1, 32a1 and second folded portions 31a4, 32a4 provided with fins 31b and 32b are arranged in the circulation air passage 20.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] Embodiments of the present invention relate to a clothes dryer.

Background Art

[0002] In a clothes dryer equipped with a heat pump, due to the increasing concern about environmental problems, the use of a flammable refrigerant with a small ozone depletion coefficient and a small global warming coefficient is being considered.

[0003] Since the amount of refrigerant enclosed in the heat pump of a clothes dryer is small, even if the refrigerant leaks from the heat pump, it is difficult for the inside of the clothes dryer housing to reach the flammable limit concentration and there is almost no possibility of developing into a fire. However, as safety measures in the case of refrigerant leakage, various measures have been proposed conventionally (for example, see Patent Document 1 below).

[0004] In Patent Document 1 below, when a refrigerant detector disposed inside a cover that covers a connection pipe connecting a compressor and an expansion device of a heat pump, and the evaporator and the condenser thereto detects a leakage of a flammable refrigerant, the compressor is stopped and an exhaust blower for discharging the leaked refrigerant to the outside is operated.

[0005] However, in Patent Document 1 below, when a flammable refrigerant leaks from the heat pump, it accumulates inside the cover. Therefore, there is a risk of reaching the flammable limit concentration when the concentration of the flammable refrigerant inside the cover cannot be correctly detected due to a failure or error of the refrigerant detector.

Prior Art Documents

Patent Documents

[0006] [[ID=3३]] [[ID=3४]]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The embodiments of the present invention have been made in consideration of the above circumstances, and aim to provide a highly safe clothes dryer equipped with a heat pump using a flammable refrigerant that can suppress ignition even if the flammable refrigerant leaks out. [Means for solving the problem]

[0008] A clothes dryer according to one embodiment comprises a drying chamber for storing clothes, a circulating air passage connected at both ends to the drying chamber, a blower for circulating air between the drying chamber and the circulating air passage, a condenser for heating the air in the circulating air passage, an evaporator for cooling and dehumidifying the air in the circulating air passage, a compressor for compressing a flammable refrigerant and supplying it to the condenser, a heat pump connected by a refrigerant transport pipe for reducing the pressure of the flammable refrigerant that has passed through the condenser, and a housing for housing the drying chamber, the circulating air passage, the blower, and the heat pump, wherein the housing has an opening that connects the inside and outside of the housing, the condenser and the evaporator each have a refrigerant pipe through which a flammable refrigerant flows and fins attached to the refrigerant pipe, and the refrigerant pipe has a plurality of straight sections to which the fins are attached and a means for connecting one end of the plurality of straight sections 1 The folded portion, one end of the plurality of straight portions and the 1 The joint that connects the folded part and , a second folded portion which is folded back at the other end of the plurality of straight portions and integrally provided with the plurality of straight portions, The plurality of straight sections and the second folded portion A clothes dryer in which the joint is located inside the circulating air passage and the connecting portion is located outside the circulating air passage. [Brief explanation of the drawing]

[0009] [Figure 1] Front view of a clothes dryer according to one embodiment, with the door removed. [Figure 2] Figure 1 is a longitudinal cross-sectional side view showing the schematic configuration of a clothes dryer. [Figure 3] Cross-sectional view AA in Figure 1 [Figure 4] Rear view showing the exterior of the clothes dryer (Figure 1) [Figure 5] BB cross-section view in Figure 3 [Figure 6] Cross-sectional view of the heat exchange section installed in the modified clothes dryer. [Modes for carrying out the invention]

[0010] One embodiment of the present invention will be described below with reference to the drawings. Note that the following embodiments are illustrative and the scope of the invention is not limited thereto. Various omissions, substitutions, and modifications can be made to the following embodiments without departing from the spirit of the invention. The following embodiments and their variations are included within the scope of the invention as described in the claims and its equivalents.

[0011] In the following explanation, left-right, front-back, and up-down directions refer to the directions when viewing the washer-dryer from the front, with the left-right direction corresponding to the width of the washer-dryer. Furthermore, unless otherwise specified, right, left, up, down, front, and back refer to the position or side of the washer-dryer when viewed from the front.

[0012] This embodiment relates to a drum-type washer-dryer that combines the functions of a washing machine and a clothes dryer. As shown in Figures 1 and 2, the housing 1 is composed of a roughly rectangular box-shaped outer casing 1a and a base plate 1b provided at its lower part.

[0013] The front of the outer box 1a has a laundry entrance / exit 3, which is an opening located approximately in the center. The laundry entrance / exit 3 is opened and closed by a door 4 that is rotatable laterally via a hinge (see Figure 2).

[0014] Inside the housing 1, as shown in Figure 2, there is a water tank 8, a circulating air passage 20 connected to the water tank 8, a blower 27 for circulating air between the water tank 8 and the circulating air passage 20, a heat pump 35 for dehumidifying and heating the air in the circulating air passage 20, and, as shown in Figure 3, a ventilation path 50 is provided outside the circulating air passage 20.

[0015] The water tank 8 is substantially cylindrical with an open front and a closed rear, and the opening at the front communicates with the laundry inlet / outlet 3. The water tank 8 is elastically supported on the base plate 1b in a horizontal axis state with its axial direction facing the front-rear direction via an elastic support mechanism. Water such as tap water is supplied from outside the machine to the water inlet provided at the upper part of the water tank 8 via a water supply valve, and the water in the water tank 8 can be drained to the outside of the machine via a drain valve from a drain port (not shown) provided at the bottom of the water tank 8.

[0016] Inside the water tank 8, a cylindrical rotary drum 14 with an open front and a closed rear is rotatably arranged. The rotary drum 14 is arranged inside the water tank 8 in a horizontal axis state with its axial direction facing the front-rear direction. A large number of holes 15 through which water and air can pass are formed in peripheral wall of the rotary drum 14, and the inside of the rotary drum 14 communicates with the water tank 8 through these holes 15.

[0017] The front opening of the rotary drum 14 also communicates with the laundry inlet / outlet 3, and the rotary drum 14 accommodates the laundry input from the laundry inlet / outlet 3. The rotary drum 14 is rotationally driven by a drum motor 17 provided on the rear surface of the water tank 8. The rotary drum 14 configured as such functions as a washing tub during the washing process, a dewatering tub during the dewatering process, and further as a drying tub ( drying chamber) during the drying operation.

[0018] As shown in FIG. 2, the water tank 8 has an exhaust port 10 provided at the lower front end of the water tank 8 and an air supply port 11 provided at a position slightly above the center of the rear surface of the water tank 8, and a circulation air duct 20 is connected to the exhaust port 10 and the air supply port 11.

[0019] [[ID=1,7]] As shown in FIGS. 2 to 4, the circulation air duct 20 includes, in order from the upstream side with respect to the air circulation direction, an exhaust duct 22, a heat exchange section 30, and an air supply duct 26. The air in the water tank 8 is exhausted from the exhaust duct 22 connected to the exhaust port 10, and the air flowing through the circulation air duct 20 is supplied into the water tank 8 from the air supply duct 26 connected to the air supply port 11.

[0020] The exhaust duct 22 extends downward from the exhaust port 10 to the lower front end of the water tank 8, and the tip (lower end) of the exhaust duct 22 is connected to the opening 42a provided on the upper surface of the heat exchange section 30.

[0021] The heat exchange section 30 includes a housing 40 placed on the base plate 1b below the water tank 8, an evaporator 31 provided inside the housing 40, and a condenser 32 disposed in the housing 40 at a distance downstream in the air circulation direction from the evaporator 31.

[0022] As shown in FIGS. 3 and 5, both the evaporator 31 and the condenser 32 provided in the heat exchange section 30 are finned tube heat exchangers each including a refrigerant pipe and fins 31b, 32b attached to the refrigerant pipe.

[0023] The refrigerant pipe is made of a material with high thermal conductivity such as copper, and is formed in a meandering shape including a plurality of straight portions 31a1, 32a1, first folded portions 31a2, 32a2 folded back in a U shape so as to connect one end of the straight portions 31a1, 32a1, joining portions 31a3, 32a3 joining one end of the straight portions 31a1, 32a1 and the first folded portions 31a2, 32a2 by brazing, and second folded portions 31a4, 32a4 folded back in a U shape at the other end of the straight portions 31a1, 32a1 and provided integrally with the straight portions 31a1, 32a1.

[0024] The fins 31b, 32b are arranged and attached to the straight portions 31a1, 32a1 of the refrigerant pipe at a predetermined pitch.

[0025] The inlet 32a5 of the refrigerant pipe of the condenser 32 is joined by brazing the exposed end on the outside after being inserted and fitted by making the diameters of each end in a size relationship with the outlet of the refrigerant transport pipe 36 connected to the discharge side of the compressor 33, and the outlet 32a6 of the refrigerant pipe of the condenser 32 is joined by brazing to one end of the refrigerant transport pipe 37 in the same manner as described above.

[0026] The refrigerant transport pipe 37 connects the condenser 32 and the evaporator 31, and is equipped with a pressure reducing section 34 that reduces the pressure of the refrigerant that has passed through the condenser 32, consisting of a capillary tube and an adjustable solenoid valve.

[0027] The other end of the refrigerant transport pipe 37 is joined to the inlet 31a5 of the refrigerant pipe of the evaporator 31 by brazing, in the same manner as described above. Furthermore, the outlet 31a6 of the refrigerant pipe of the evaporator 31 is joined to the refrigerant transport pipe 38, which is connected to the suction side of the compressor 33, also by brazing, in the same manner as described above.

[0028] As described above, the evaporator 31 and condenser 32 are connected in a ring shape to the compressor 33 and pressure reducing unit 34 by refrigerant transport pipes 36, 37, and 38, thereby constituting a heat pump 35.

[0029] The housing 40 includes a lower member 41 that opens upward and a part that closes the upper opening of the lower member 41. The device comprises a lid 42 and a sealing member 43 that seals the space between the lower member 41 and the lid 42.

[0030] The lower member 41 is a flattened, container-shaped member with a space formed inside for installing the evaporator 31 and condenser 32. The lower member 41 partitions the air passage through which air flows in the circulating air passage 20 between itself and the lid 42, and also receives the dehumidified water generated in the evaporator 31. The bottom surface 41a of the lower member 41 is gently sloped downwards toward the rear, guiding the dehumidified water generated in the evaporator 31 to the drainage means 44 provided on the rear surface 1c of the outer box 1a for drainage.

[0031] Such a housing 40 is placed on the base plate 1b, positioned to one side (for example, the left side) in the space formed between the water tank 8 and the base plate 1b. An opening 42a for connecting the lower end of the exhaust duct 22 is provided at the front end of the lid 42, and an air supply duct 26 is connected to the rear end of the lower member 41, so that air flows through the inside of the housing 40 toward the rear.

[0032] The compressor 33, although not shown in detail, comprises a compression mechanism and a motor, and the motor is supplied with a drive power supply at a set frequency by an inverter power supply. As a result, the motor rotates at a rotational speed corresponding to the supplied frequency, driving the compressor 33 at the desired set output.

[0033] The compressor 33 and the pressure reducing unit 34 are positioned away from the heat exchange unit 30 in a direction perpendicular to the direction of airflow in the heat exchange unit 30. In other words, the compressor 33 and the pressure reducing unit 34 are located in the space formed between the water tank 8 and the base plate 1b, to the side (right side) of the heat exchange unit 30.

[0034] The heat pump 35 is filled with a hydrocarbon-based flammable refrigerant such as isobutane (hereinafter sometimes referred to as the refrigerant), and as the compressor 33 operates, the refrigerant circulates, causing the evaporator 31 to cool and dehumidify the air flowing inside the housing 40, and the condenser 32 to heat the air that has been dehumidified by the evaporator 31.

[0035] A sirocco fan 27a is provided at the connection point between the heat exchange unit 30 and the air supply duct 26, on the downstream side in the air circulation direction of the heat exchange unit 30, and connected to the air supply port 11 of the water tank 8 via an air supply duct 26.

[0036] The sirocco fan 27a, together with the fan motor 27b located in the space between the water tank 8 and the base plate 1b, constitutes the blower 27. The fan motor 27b is positioned on the rear side (rear right) of the heat exchange unit 30 such that its rotating shaft 27c extends backward. The rotating shaft 27c of the fan motor 27b penetrates the back surface 1c of the outer casing 1a, and the sirocco fan 27a is attached to its tip. When the sirocco fan 27a rotates, powered by the fan motor 27b, it draws in the dehumidified and heated air from the heat exchange unit 30 and discharges it into the air supply duct 26.

[0037] As shown in Figures 3 and 4, the air supply duct 26 consists of a vertically extending flow path formed between the duct cover 28 attached to the back surface 1c of the outer casing 1a and the back surface 1c of the outer casing 1a. Air discharged from the sirocco fan 27a flows upward through the air supply duct 26 and is supplied to the water tank 8 and then to the rotating drum 14 through the inlet 29 provided on the back surface 1c of the outer casing 1a.

[0038] The ventilation path 50 is a space formed outside the water tank 8 and the circulating air passage 20 inside the housing 1, and is independent of the circulating air passage 20, with air flow between it and the circulating air passage 20 being substantially blocked. It is a space.

[0039] The ventilation path 50 houses the compressor 33 and pressure reducing unit 34 that constitute the heat pump 35, as well as the fan motor 27b of the blower 27. The ventilation path 50 also includes a first opening 51 provided to the side (right) of the heat exchange unit 30 where the compressor 33 and fan motor 27b are located, penetrating the base plate 1b vertically, and a second opening 52 (see Figure 4) provided on the back surface 1c of the outer box 1a above the first opening 51, and communicates with the external space of the housing 1 through the first opening 51 and the second opening 52.

[0040] In this ventilation path 50, when the heat pump 35 and blower 27 are operating, heat generated from the compressor 33 and fan motor 27b creates an upward airflow, and the air taken in from outside the housing 1 circulates within the ventilation path 50 so that air is taken in from outside the housing 1 through the first opening 51 and discharged to the outside of the housing 1 through the second opening 52.

[0041] In Figure 3, reference numeral 53 denotes a capacitor for motor drive provided in the ventilation path 50, which supplies power to the drum motor 17 that rotates the rotating drum 14. The capacitor 53 is housed in an explosion-proof case with the connection terminals to which lead wires connecting to the drum motor 17 are soldered, i.e., the live parts, facing downwards, and is fixed to the base plate 1b on the side of the heat exchange section 30. Between the connection terminals, which are the live parts of the capacitor 53, an electrical component provided on the base plate 1b, and the joints 31a3, 32a3 of the evaporator 31 and condenser 32, a partition 54 is provided that rises upward from the base plate 1b. The partition 54 protrudes above the capacitor 53 and separates the capacitor 53 from the joints 31a3, 32a3.

[0042] In a washing and drying machine with the above configuration, the evaporator 31 and condenser 32 are arranged such that the first folded portions 31a2, 31a2 and the joint portions 31a3, 31a3 are located in the ventilation path 50, and the straight portions 31a1, 32a1, the second folded portions 31a4, 32a4 and the fins 31b, 32b are located within the heat exchange section 30 that constitutes the circulating air passage 20.

[0043] Specifically, the housing 40, partitioned by the lower member 41 and the lid 42, houses the straight sections 31a1, 32a1, the second folded sections 31a4, 32a4, and the fins 31b, 32b of the evaporator 31 and condenser 32, while the first folded sections 31a2, 32a2 and the joint sections 31a3, 32a3 are housed in the water receiving section 45, which is provided adjacent to the outside of the housing 40.

[0044] As shown in Figure 5, the water receiving section 45 has a container-like shape with a bottom surface 45a provided below the first folded sections 31a2, 32a2 and the joint sections 31a3, 32a3, and a peripheral wall 45b rising upward from its periphery, with an opening 45c formed at the top.

[0045] The water receiving section 45 is located between the compressor 33 and the depressurization section 34 and the heat exchange section 30, adjacent to one side of the heat exchange section 30 where the compressor 33 and the depressurization section 34 are located, and is separated from the inside of the housing 40 by a partition wall 46 that extends parallel to the air circulation direction in the housing 40.

[0046] The partition wall 46 separating the water receiving section 45 and the housing 40 has one end of each straight section 31a1, 32a1 that penetrates it in an airtight manner, while the first folded sections 31a2, 32a2 and the joint sections 31a3, 32a3 protrude from the partition wall 46 into the interior of the water receiving section 45. The upper end of the partition wall 46 is provided with a cover 42 sandwiching a sealing member 43. As a result, the interior of the water receiving section 45 communicates with the ventilation path 50 through an opening 45c provided on the upper surface, but a space is formed where air circulation is substantially blocked from the interior of the housing 40.

[0047] In this embodiment, in addition to the first folded portions 31a2, 32a2 and the joint portions 31a3, 32a3, the inlet 31a5 and outlet 31a6 of the refrigerant pipe of the evaporator 31, and the inlet 32a5 and outlet 32a6 of the refrigerant pipe of the condenser 32, as well as the joint portions between these and the refrigerant transport pipes 36, 37, 38, are also provided inside the water receiving portion 45.

[0048] In the washing machine and dryer of this embodiment as described above, the evaporator 31 and condenser 32 are arranged such that the first folded sections 31a2, 31a2 and the joint sections 31a3, 31a3 are located in the ventilation path 50, and the straight sections 31a1, 32a1, the second folded sections 31a4, 32a4 and the fins 31b, 32b are located within the heat exchange section 30 that constitutes the circulating air passage 20. The joint sections 31a3, 32a3, which are joined by brazing, have a higher possibility of refrigerant leakage compared to other parts of the refrigerant pipes and refrigerant transport pipes 36, 37, 38. However, in the washing machine and dryer of this embodiment, even if flammable refrigerant leaks from the joint sections 31a3, 32a3, it is difficult for the flammable refrigerant to enter the circulating air passage 20, where ignition sources such as static electricity are likely to occur, thus suppressing ignition.

[0049] In this embodiment, since the base plate 1b on which the heat exchange unit 30 and compressor 33 are mounted is provided with a first opening 51, if the flammable refrigerant has a higher specific gravity than air, the leaked refrigerant will travel along the base plate 1b and be discharged to the outside of the housing 1 through the first opening 51.

[0050] Furthermore, when the heat pump 35 and blower 27 are operating, the rising airflow generated in the ventilation path 50 by the heat from the compressor 33 and fan motor 27b allows the flammable refrigerant to be discharged to the outside of the housing 1.

[0051] Furthermore, in this embodiment, since the water receiving section 45 is provided so as to cover the lower part of the joints 31a3, 32a3 and the first folded parts 31a2, 32a2, even if condensation water adhering to the first folded parts 31a2 and joints 31a3 of the evaporator 31 drips down when the heat pump 35 is operating, it is possible to prevent the condensation water from reaching the fan motor 27b, compressor 33, condenser 53, etc., which are mounted on the base plate 1b. Moreover, since the water receiving section 45 has an opening 45c on its upper side, even if flammable refrigerant leaks from the joints 31a3, 32a3, it can be discharged to the outside of the housing 1 through the ventilation path 50 via the opening 45c.

[0052] Furthermore, in this embodiment, a sealing member 43 is provided in the partition wall 46 that separates the water receiving section 45 from the housing 40 of the heat exchange section 30, thereby sealing the housing 40 and the water receiving section 45. This prevents air from flowing between the housing 40 and the water receiving section 45. As a result, even when the heat exchange section 30 is under negative pressure during the operation of the blower 27, it is possible to prevent flammable refrigerant leaking from the joints 31a3 and 32a3 from entering the heat exchange section 30 from the water receiving section 45.

[0053] Furthermore, in this embodiment, since a partition is provided between the condenser 53 placed on the base plate 1b and the joints 31a3 and 32a3 of the evaporator 31 and condenser 32, even if refrigerant leaks from the joints 31a3 and 32a3 and flows along the base plate 1b, it is possible to prevent flammable refrigerant from reaching the vicinity of the condenser 53, which could become an ignition source such as sparks, particularly the connection terminals of the condenser 53, which are the charging part.

[0054] (Example of change 1) In the embodiments described above, the case in which the joints 31a3, 32a3 and the first folded portions 31a2, 32a2 provided on the outside of the heat exchange section 30 in the evaporator 31 and condenser 32 are exposed to the ventilation path 50 has been explained. However, for example, as shown in Figure 6, a porous material such as foamed urethane may be filled into the water receiving section 45 and the joints 31a3, 32a3 and the first folded portions 31a2, 32a2 may be covered with the porous material 55. In such a case, heat leakage from the joints 31a3, 32a3 and the first folded portions 31a2, 32a2 can be suppressed and the thermal efficiency in the heat exchange section 30 can be improved. Furthermore, even if refrigerant leaks from the joints 31a3, 32a3, the refrigerant will be slowly released into the ventilation path 50, preventing the inside of the housing 1 from reaching the ignition limit concentration.

[0055] (Example of change 2) In the above-described embodiment, a washing machine and dryer without a refrigerant detection sensor was explained. However, for example, a gas sensor that detects refrigerant leaking from the heat pump 35 may be provided in the ventilation path 50 or the circulating air passage 20. [Explanation of Symbols]

[0056] 1...Housing, 1a...Outer box, 1b...Base plate, 8...Water tank, 10...Exhaust port, 11...Air intake port, 17...Drum motor, 20...Circulating air passage, 22...Exhaust duct, 26...Air intake duct, 27...Blower, 27a...Sirocco fan, 27b...Fan motor, 30...Heat exchange section, 31...Evaporator, 31a1...Straight section, 31a2...First return section, 31a3...Joint section, 31a4...Second return section, 31b...Fin, 32...Condenser, 32a1...Straight section, 32a 2...First folded section, 32a3...Joint section, 32a4...Second folded section, 32b...Fin, 33...Compressor, 35...Heat pump, 36...Refrigerant transport pipe, 37...Refrigerant transport pipe, 38...Refrigerant transport pipe, 40...Housing, 41...Lower member, 42...Lid, 43...Sealing member, 45...Water receiving chamber, 45c...Opening, 46...Partition wall, 50...Ventilation path, 51...First opening, 52...Second opening, 53...Condenser, 54...Screen, 55...Porous body

Claims

[Claim 1] A drying room for storing clothes, A circulating air passage whose ends are connected to the drying chamber, A blower that circulates air between the drying chamber and the circulating air passage, A heat pump comprising a condenser for heating the air in the circulating air passage, an evaporator for cooling and dehumidifying the air in the circulating air passage, a compressor for compressing a flammable refrigerant and supplying it to the condenser, and a depressurization means for reducing the pressure of the flammable refrigerant that has passed through the condenser, all connected by a refrigerant transport pipe, In a clothes dryer comprising a drying chamber, a circulating air passage, a blower, and a housing for the heat pump, The housing has an opening that connects the inside and outside of the housing, The condenser and the evaporator each include a refrigerant pipe through which a flammable refrigerant flows, and fins attached to the refrigerant pipe, the refrigerant pipe comprising a plurality of straight sections to which the fins are attached, a first folded section provided to connect one end of the plurality of straight sections, a joint section joining one end of the plurality of straight sections to the first folded section, and a second folded section folded at the other end of the plurality of straight sections and integrally provided with the plurality of straight sections. A clothes dryer in which the plurality of straight sections and the second folded section are located inside the circulating air passage, and the joint is located outside the circulating air passage.

Images