JP6242586B2 - Oxygen reduction device - Google Patents

Description

  Embodiments described herein relate generally to an oxygen reduction device.

  Conventionally, the CA (Controlled Atmosphere) storage method includes a gas replacement method that is widely used in the food industry, a vacuum method that reduces oxygen by reducing the pressure, and a polymer electrolyte membrane that reduces oxygen in the CA storage room. For example, a polymer electrolyte method, an adsorption method using an oxygen adsorbent, and the like.

  The gas replacement method is a method in which a gas typified by nitrogen or carbon dioxide gas is stored by being replaced with air, and is widely used for maintaining freshness in the distribution process of food and vegetables.

  The vacuum method is a method of depressurizing as a method of reducing oxygen in order to prevent oxidation of food. Since the performance correlates with the degree of vacuum, the strength of the storage container and the capacity of the vacuum pump are required, which makes the apparatus relatively large.

  The method using an oxygen adsorbent is also widely used in the distribution process of confectionery and the like as in the gas replacement method. However, if the adsorbent breaks through adsorption, the effect is lost and the life is short.

  In the polymer electrolyte membrane method, water is electrolyzed in the anode layer to form hydrogen ions, and the hydrogen ions move through the polymer electrolyte membrane to reach the cathode layer, react with oxygen in the storage container and react with the water. It generates oxygen and consumes oxygen. Therefore, there is a merit that the pressure change is small and the strength of the storage container is not necessary.

JP 2004-218924 A Japanese Patent Laid-Open No. 9-287869 JP-A-6-184237

  However, in the polymer electrolyte membrane method, since heat is generated by electrolysis, there is a problem in that the internal temperature rises when the heating source is held inside the refrigerator.

  Therefore, in view of the above problems, an embodiment of the present invention aims to provide an oxygen reduction device in which the temperature does not increase even if the oxygen reduction device uses a polymer electrolyte membrane method.

The present embodiment relates to an oxygen reduction apparatus for reducing oxygen in an oxygen reduction chamber, a polymer electrolyte membrane, an anode layer provided on one side of the polymer electrolyte membrane, and the other side of the polymer electrolyte membrane. Provided on the anode layer side, a cathode layer that leads to the oxygen reduction chamber, a positive current collector that energizes the anode layer, a negative current collector that energizes the cathode layer, and the anode layer side. An oxygen reduction unit having a water supply portion is housed in a heat insulating case, and the wall of the case covers the cathode surface of the oxygen reduction unit on the cathode layer side, and the wall of the case and the oxygen reduction unit A reaction space is formed between the cathode surface of the unit, the case has an exhaust port for diffusing oxygen generated by the oxygen reduction device, and the exhaust port is located below the polymer electrolyte membrane. Open That is a reduced oxygen apparatus.

It is a longitudinal cross-sectional view of the refrigerator of Embodiment 1. 1 is an enlarged longitudinal sectional view of an oxygen reduction device according to Embodiment 1. FIG. It is a disassembled perspective view of an oxygen reduction unit. It is a front view of an oxygen reducing device. It is a rear view of an oxygen reducing device. It is a longitudinal cross-sectional view of an oxygen reducing device. It is a longitudinal cross-sectional view of a refrigerator compartment lower part and a vegetable compartment, Comprising: It is the state which closed the door of the vegetable compartment. Similarly, the vegetable room door is pulled out. Similarly, the vegetable room door and the oxygen-reducing container are pulled out. It is a refrigeration cycle of a refrigerator. It is a block diagram of a refrigerator. It is an expansion longitudinal cross-sectional view of the oxygen reduction apparatus of the modification 1 of Embodiment 1. FIG. It is an expanded longitudinal cross-sectional view of the oxygen reduction apparatus of the modification 2 of Embodiment 1. FIG. It is a longitudinal cross-sectional view of the oxygen reduction apparatus of Embodiment 2. It is a disassembled perspective view of an oxygen reduction unit. It is a disassembled perspective view of an oxygen reducing device. It is a perspective view of a front case. It is a semi-longitudinal cross-sectional perspective view of a rear case. It is a longitudinal cross-sectional view of a water supply apparatus. It is a figure of the table showing an experimental result. It is a perspective view of the front case of the modification 1 of Embodiment 2. FIG. It is a perspective view of the front case of the modification 2 of Embodiment 2. FIG. It is a perspective view of the front case of the modification 3 of Embodiment 2. FIG. It is a perspective view of the front case of the modification 4 of Embodiment 2. FIG.

  Hereinafter, an oxygen reduction device for a refrigerator according to an embodiment will be described with reference to the drawings.

Embodiment 1

  The oxygen reduction apparatus 102 of the refrigerator 10 of Embodiment 1 is demonstrated based on FIGS. The refrigerator 10 of this embodiment has an oxygen reduction chamber 100, and the oxygen reduction chamber 100 has an oxygen reduction device 102.

(1) Structure of refrigerator 10 The structure of the refrigerator 10 is demonstrated based on FIG. FIG. 1 is a longitudinal sectional view of the entire refrigerator 10.

  The cabinet 12 of the refrigerator 10 is a heat insulation box, and is formed of an inner box and an outer box, and a heat insulating material is filled between the inner box and the outer box. The inside of the cabinet 12 has a refrigerator compartment 14, a vegetable compartment 16, a small freezer compartment 18 and a freezer compartment 20 in order from the top, and an ice making room (not shown) is provided beside the small freezer compartment 18. A heat insulating partition 36 is provided between the vegetable compartment 16, the small freezer compartment 18 and the ice making compartment. The refrigerator compartment 14 and the vegetable compartment 16 are partitioned by a horizontal partition 38. A front door 14a is provided on the front side of the refrigerator compartment 14, and drawer doors 16a, 18a and 20a are provided in the vegetable compartment 16, the small freezer compartment 18, the freezer compartment 20 and the ice making compartment, respectively. .

  A machine room 22 is provided at the bottom of the back surface of the cabinet 12, and a compressor 24 and the like constituting the refrigeration cycle are placed thereon. A control plate 26 is provided on the upper back of the machine room 22.

  A refrigeration evaporator (hereinafter referred to as “R EVA”) 28 is provided from the lower back of the refrigerator compartment 14 to the back of the vegetable compartment 16, and a refrigeration blower (hereinafter referred to as “R fan”) 30 is provided below the evaporator. Is provided. A freezing evaporator (hereinafter referred to as “F EVA”) 32 is provided from the back of the small freezer 18 to the back of the freezer 20, and a freezing fan (hereinafter referred to as “F fan”) 34 is provided above the evaporator. It has been. The cold air cooled by the R evaporator 28 is sent to the refrigerator compartment 14 and the vegetable compartment 16 by the R fan 30. The cold air cooled by the F-evapor 32 is blown by the F fan 34 to the small freezer 18, ice making room, and freezer 20.

  A refrigeration room sensor (hereinafter referred to as “R sensor”) for detecting the internal temperature of the refrigeration room 14 is provided on the back surface of the refrigeration room 14, and the internal temperature of the freezer room 20 is provided on the back surface of the freezer room 20. A refrigerating sensor (hereinafter referred to as “F sensor”) 35 is provided.

(2) Cold room 14 and vegetable room 16
Next, the structure of the refrigerator compartment 14 and the vegetable compartment 16 is demonstrated.

  As shown in FIG. 1, the refrigerator compartment 14 is provided with a plurality of shelves 40, and a chilled chamber 44 having a drawer-type chilled container 42 is provided at the lower part. The chilled chamber 44 is a low temperature chamber and stores meat and fish. A plurality of door pockets 46 are provided on the back surface of the door 14 a of the refrigerator compartment 14.

  As shown in FIGS. 7 to 9, the vegetable compartment 16 is provided with a drawer-type vegetable container 48 and is supported by a pair of left and right moving rails 50, 50 protruding rearward from the back surface of the door 16 a of the vegetable compartment 16. The pair of left and right moving rails 50, 50 move in the horizontal direction on fixed rails 52, 52 provided on the right inner wall and the left inner wall of the vegetable compartment 16, respectively.

  A hypoxic chamber 100 is provided at the rear of the partition 38 that hits the ceiling of the vegetable compartment 16. An oxygen reduction device 102 is provided at the rear of the oxygen reduction chamber 100. The oxygen reduction chamber 100 and the oxygen reduction device 102 will be described in detail later.

(3) Hypoxic chamber 100
Next, the structure of the oxygen reduction chamber 100 will be described with reference to FIGS. 1 and 7 to 9.

  As shown in FIG. 1, the oxygen reduction chamber 100 includes a container storage unit 104 that is suspended from a partition 38, an oxygen reduction container 106 that can be drawn forward from the container storage unit 104, and the oxygen reduction device 100. .

  As shown in FIGS. 7-9, the container storage part 104 is suspended by the partition body 36, the ceiling surface of the container storage part 104 is comprised by the partition body 36, the front surface is opened, a back surface, both side surfaces, and a bottom surface are covered. I have it.

  As shown in FIGS. 7 to 9, the oxygen reduction container 106 can be pulled out from the front surface of the opened container housing portion 104, and the front surface of the oxygen reduction container 106 also serves as the door 108. A frame-like gasket 110 is provided on the four circumferences of the back surface of the door 108, and the oxygen reduction chamber 100 is hermetically sealed when the oxygen reduction container 106 is stored in the container storage portion 104.

As shown in FIGS. 7 to 9, the CO ₂ sensor 72 is provided on the front side of the back surface of the container storage unit 104. When the food 58 such as vegetables is stored in the oxygen reduction chamber 100 and the vegetables breathe and discharge CO ₂ , the CO ₂ sensor 72 detects the discharged CO ₂ and outputs a signal. Thereby, it can be detected that the food 58 is stored in the oxygen reduction chamber 100.

  As shown in FIGS. 7 to 9, a vent hole 112 is opened on the rear rear side of the container housing portion 104, and the oxygen reduction device 102 is attached to the position of the vent hole 112.

(4) Oxygen reduction device 102
Next, the structure of the oxygen reduction device 102 will be described with reference to FIGS.

  In the oxygen reduction device 102 using the polymer electrolyte membrane method, an oxygen reduction unit 115 is provided inside a box-shaped case 114 having heat insulation properties.

(4-1) Oxygen reduction unit 115
First, the oxygen reduction unit 115 is demonstrated based on FIG.2 and FIG.3. FIG. 2 is a longitudinal sectional view of the oxygen reduction device 102, and FIG. 3 is an exploded perspective view of the oxygen reduction unit 115. In FIGS. 2 and 3, the thickness of each member is thin, but the thickness is enlarged for easy understanding.

A polymer electrolyte membrane (hereinafter simply referred to as “electrolyte membrane”) 116 is provided in the vertical direction, an anode layer 118 is provided at the rear of the electrolyte membrane 116, and a cathode layer 120 is provided at the front of the electrolyte membrane 116. ing. The cathode layer 120 is a laminate of a carbon catalyst and carbon paper. The anode layer 118 and the cathode layer 120 carry platinum catalysts. The electrolyte membrane 116, the anode layer 118, and the cathode layer 120 are integrally joined using a hot press or the like. A positive current collector 122 is provided behind the anode layer 118, and a negative current collector 124 is provided in front of the cathode layer 120. Both current collectors 122 and 124 are mesh-like titanium films whose surfaces are plated with platinum. The current collector 122 performs positive energization on the anode layer 118, and the current collector 124 provides negative energization on the cathode layer 120. Do. Both current collectors 122 and 124 are energized from electric wires 158 and 160. Further, an insulator 125 is provided between the current collectors 122 and 124 so that the current collectors 122 and 124 do not contact each other. The insulator 125 has a frame shape, and the electrolyte membrane 116, the anode layer 118, and the cathode layer 120 are accommodated therein.

A water repellent layer 126 is provided behind the positive current collector 122. The water repellent layer 126 is provided inside the frame-shaped gasket 126. Further, a water repellent layer 130 is also provided in front of the negative current collector 124, and this water repellent layer 130 is also provided inside the frame-shaped gasket 131. As the water repellent layers 126 and 130, polymer films are used. Although many polymer films are water-repellent, it is necessary to allow water vapor to pass through. Therefore, depending on the material, it is necessary to adjust the thickness. As a property of allowing water vapor to pass without passing through water, PTE film or A nonwoven fabric using a water-repellent resin is preferable.

  A sheet-like water supply body 128 is disposed behind the water-repellent layer 126. As this water supply body 128, it is a nonwoven fabric etc., for example.

  The members stacked in order as described above are sandwiched and fixed by a pair of front and rear fixing members 132 and 134. The rear fixing member 132 disposed on the anode side has a rectangular parallelepiped shape, and has an exhaust port 136 having a rectangular cross section at the bottom. As shown in FIG. 2, the exhaust port 136 penetrates in the front-rear direction. On the other hand, the front fixing member 134 attached to the cathode layer side also has a rectangular parallelepiped shape, and has an opening 138 in the center. The opening 138 has a strip shape in which a plurality of slit-like holes penetrating in the vertical direction are arranged. The opening 138 corresponds to the position of the vent hole 112 of the container storage unit 104.

  The oxygen reduction unit 115 is comprised by the above member. The fixing member 132 and the fixing member 134 are fixed by several screws (not shown). The fixing member 132 and the fixing member 134 are formed of, for example, ABS resin that requires rigidity in order to prevent warping of each of the sandwiched members.

  In the oxygen reduction unit 115, as shown in FIG. 2, the gasket 131 having the water repellent layer 130, the negative current collector 124, and the side surfaces of the cathode layer 120 are sealed and packed with resin.

  The thickness in the front-rear direction of the fixing member 132 and the fixing member 134 is, for example, 10 mm, the thickness of the water supply body 128 is, for example, 0.2 mm, the thickness of the water-repellent layer 126 and the water-repellent layer 130 is, for example, 0.2 mm, The thickness of the gasket 131 is, for example, 0.2 mm, the thickness of the anode layer 118 is, for example, 0.25 mm, the thickness of the electrolyte membrane 116 is, for example, 0.2 mm, the thickness of the cathode layer 120 is, for example, 0.25 mm, and the thickness of the insulator 126 is For example, the thickness of the current collector 122 and the current collector 124 is 0.7 mm, for example, 0.5 mm.

(4-2) Case 114
The oxygen reduction unit 115 described above is accommodated in a box-shaped case 114. The case 114 will be described with reference to FIGS. 4 is a front view of the case 114, FIG. 5 is a rear view, and FIG. 6 is a longitudinal sectional view.

  Case 114 is formed of a heat insulating member. For example, the thickness is 5 mm. The case 114 includes a unit storage portion 140 for storing the oxygen reduction unit 115 and a water passage portion 142 provided on the side of the unit storage portion 140. The cylindrical water passage part 142 is provided with a water purification part 144 made of an ion exchange resin. Condensed water generated in the R-eva 28 is supplied from the water supply pipe 152 to the upper surface of the water passage portion 142 by the pump 146 through the hose 56. The water purified by the ion exchange resin water purifier 144 flows from the bottom surface of the water passage 142 into the lower part of the unit housing 140. As shown in FIG. 6, the lower part of the unit storage part 140 has a water holding part 148 that is inclined downward toward the center, and the water flowing out from the water purifying part 144 accumulates in the water holding part 148.

  As shown in FIG. 5, a diffusion port 150 for diffusing oxygen generated by the oxygen reduction unit 115 and a drain pipe 154 for flowing water overflowing from the water holding unit 148 are connected to the back surface of the case 114. Has been. The water from the drain pipe 154 is drained to an evaporating dish, for example.

  A water supply body 128 that hangs down from the oxygen reduction unit 115 is immersed in the water accumulated in the water holding unit 148.

  The fixing member 134 of the oxygen reduction unit 115 is fixed to the back surface of the container storage unit 104, and the case 114 is also fixed to the container storage unit 104.

(5) Refrigeration cycle Next, the structure of the refrigeration cycle will be described with reference to FIG.

  In the refrigeration cycle, a condenser 60 and a three-way valve 62 are connected in order from the discharge side of the compressor 24. A refrigeration capillary tube 64 and an R-eva 28 are connected to one outlet of the three-way valve 62. The other outlet of the three-way valve 62 is connected to the freezing capillary tube 66 and the F-evapor 32. Thereafter, the refrigerant flow path becomes one, and reaches the suction side of the compressor 24 through the suction pipe 68. The refrigerant is compressed by the compressor 24 to be changed into a high-temperature and high-pressure gaseous refrigerant, and becomes a liquid state while releasing heat from the condenser 60. The liquid refrigerant is sent to the refrigeration capillary tube 64 or the freezing capillary tube 66 by the three-way valve 62, where it is depressurized so as to be easily vaporized, and then vaporized by the R EVA 28 or F EVA 32, and from the surroundings. Cold is generated by taking away heat.

(6) Electrical configuration of refrigerator 10 Next, the electrical configuration of the refrigerator 10 will be described based on the block diagram of FIG.

The control plate 26 is provided with a control unit 70 made of a microcomputer. The control unit 70 is connected to the compressor 24, the three-way valve 62, the R fan 30, the F fan 34, the oxygen reducing device 102, the pump 103, the R sensor 31, the F sensor 35, and the CO ₂ sensor 72.

  This control part 70 controls the refrigerating cycle demonstrated above using the inverter motor of the compressor 24, and the three-way valve 62, the refrigerator compartment 14 is 2 degreeC-4 degreeC, the vegetable room is 5 degreeC-7 degreeC, and a chilled room 44 is controlled to 0 ° C. to 1 ° C., and the small freezer 18, ice making chamber, and freezer 20 are controlled to −20 ° C. to −25 ° C.

(7) Operation State of Oxygen Reduction Device 102 The operation state of the oxygen reduction device 102 will be described with reference to FIGS.

  First, as shown in FIG. 7, when the vegetable compartment 16 is cooled, the door 16 a of the vegetable compartment 16 is closed, and the oxygen-reducing container 106 is accommodated in the container accommodating portion 104 for the oxygen-reducing chamber 100. . When the oxygen reduction container 106 is stored in the container storage portion 104, the interior of the oxygen reduction chamber 100 becomes a sealed space by the gasket 110.

  Next, as shown in FIG. 6, the pump 146 supplies the defrosted water generated by the R EVA 28 to the upper portion of the water passage portion 142 via the hose 56 and the water supply pipe 152. The supplied water flows out from the bottom of the water passage portion 142 through the water purification portion 144 inside the water passage portion 142 and accumulates in the water holding portion 148. The water supply body 128 immersed in the water of the water holding unit 148 sucks up the accumulated water.

Next, as shown in FIG. 7, when the food 58 is stored in the oxygen-reducing chamber 100, the food 58 breathes and emits CO ₂ . Then, the CO ₂ sensor 72 detects the CO ₂ , and the control unit 70 starts energizing the current collectors 122 and 124 or increases the value of the energized current. Further, the internal temperature of the oxygen-reducing chamber 100 is higher than the internal temperature 1 ° C. of the chilled chamber 44. That is, since the oxygen-reducing chamber 100 is provided inside the vegetable compartment 16, it becomes the same as the inside temperature of the vegetable compartment 16, for example, 5 ° C to 7 ° C. As a result, the food 58 such as vegetables stored therein can prevent a low-temperature failure due to the internal temperature being too low.

  Next, as shown in FIGS. 2 and 3, the air in the oxygen reduction container 106 is supplied through the vent 112 of the oxygen reduction chamber 100 and the opening 138 of the fixing member 134, and the current collectors 122 and 124 are energized. Therefore, oxygen reduction is performed from the inflowing air, and the oxygen reduction chamber 100 becomes a CA storage chamber. In the anode layer 118 and the cathode layer 120, the oxygen reduction reaction as in the following formulas (1) and (2) is performed.

Anode layer 2H ₂ O → O ₂ + 4H ⁺ + 4e ⁻ (1)

Cathode layer: O ₂ + 4H ⁺ + 4e ⁻ → 2H ₂ O (2)

Explaining this oxygen reduction reaction formula, water vapor that has passed through the water-repellent layer 126 from the water supply body 128 is electrolyzed in the anode layer 118 to form hydrogen ions, and the hydrogen ions move in the electrolyte membrane 116 and move to the cathode layer 120. And reacts with oxygen inside the oxygen-reducing chamber 100 to produce water and consume oxygen. Thereby, oxygen reduction is performed inside the oxygen reduction container 106, and the food 58 can be stored in CA.

  Next, as shown in FIGS. 2, 5, and 6, oxygen generated in the anode layer 118 of the oxygen reduction unit 115 first passes through the exhaust port 136 of the fixing member 132 and then diffuses from the diffusion port 150. The

  Here, the water repellent layer 126 suppresses the amount of water that moves from the water supply body 128 to the anode layer 118 and does not move it, but allows only gaseous water vapor to pass therethrough. This prevents liquid water from entering the anode layer 118 and prevents flooding.

  Further, by providing the water repellent layer 130 in front of the cathode layer 120, water is generated in the cathode layer 120 when the oxygen reducing chamber 100 is deoxygenated. This water is pure water generated by a chemical reaction. is there. Since the generated water is accumulated in the cathode layer 120 and more water than the anode layer 118, the water returns to the anode layer 118 through the electrolyte membrane 116. Therefore, pure water can be supplied to the anode layer 118 side, and the supply amount to the water supply body 128 can be reduced.

  Note that the control unit 70 controls the oxygen concentration by the oxygen reduction device 102 so that it is not less than 10%. This is effective even when the oxygen concentration of 10% is sufficient for the preservation of the food 58 such as vegetables, and a large amount of power is required to reduce the concentration to 10% or less. This is because the influence on the human body is undesirable when breathing.

  Next, as shown in FIG. 8, when the door 16a of the vegetable compartment 16 is pulled forward, the vegetable container 48 also moves forward. However, since the oxygen reduction container 106 of the oxygen reduction chamber 100 is stored in the container storage unit 104, the oxygen reduction state is maintained.

  Next, as shown in FIG. 9, when the oxygen reduction container 106 of the oxygen reduction chamber 100 is pulled forward, the oxygen reduction state is released and the food 58 stored in the oxygen reduction container 106 can be taken out.

(8) Effect According to this embodiment, since the case 114 of the oxygen reduction device 102 has heat insulation properties, electrolysis is performed in the oxygen reduction unit 115, and heat generated thereby can be transmitted to the vegetable compartment 16. Absent. Therefore, the internal temperature of the vegetable compartment 16 is not increased.

  In addition, since the diffusion port 150 is provided at the lower back of the case 114, the heat generated by the electric reaction is accumulated at the upper part of the unit housing portion 140, and the heat is not transmitted to the outside from the diffusion port 150 at the lower part. Further, since oxygen is a molecule having a molecular weight of 32 and is expected to be heavier than air and diffuse downward, it is efficient to provide the exhaust port 136 and the diffusion port 150 below the oxygen reduction device 102.

  Further, since the oxygen reduction unit 115 is surrounded by the heat insulating case 114, the inside of the case 114 is warmed by the heat of electrolysis, and the water sucked up by the water supply body 128 is easily evaporated, and stable hydrogen ions Supply becomes possible.

  Further, since the water holding portion 148 is provided inside the case 114, no special parts or space for storing water is required.

  Further, since the side surface of the cathode layer 120 is sealed with the resin 156, air in the oxygen reduction container 106 is supplied through the vent 112 and the opening 138, and only oxygen can be converted into water from the air.

  Further, since the electrolyte membrane 116, the anode layer 118, the cathode layer 120, the current collectors 122 and 124, and the water repellent layers 126 and 130 are sandwiched between the fixing member 132 and the fixing member 134, these members can be fixed integrally. Although each member is a thin layer, since it is clamped by the fixing members 132 and 134 from both sides, uniform contact of each member can be ensured without warping back. In particular, the fixing member 132 and the fixing member 134 have a strong rigidity at the portion that hits each member, and can prevent warping of each member. Therefore, a uniform contact area can be ensured.

  Further, since the opening 138 of the fixing member 134 on the cathode layer 120 side has a strip shape, the strength of pressing the cathode layer 124 can be maintained as it is, and an opening area through which oxygen can pass can be secured.

  Moreover, since the water purifying part 144 of the ion exchange resin is provided in the water passage part 142, the water supplied to the water supply body 128 can remove the influence due to the water quality of the defrost water, and the deterioration of the oxygen reduction apparatus 102 can be prevented. Can be prevented.

  Further, the oxygen-reducing chamber 100 is provided inside the vegetable compartment 16 so that the temperature inside the oxygen-reducing chamber 100 is equal to or higher than the temperature inside the chilled chamber 44. Therefore, the internal temperature becomes 5 ° C. to 7 ° C., and the food 58 such as vegetables stored in the oxygen reduction chamber 100 does not cause a low temperature failure. On the other hand, the chilled chamber 44 is normally controlled at a temperature of about 1 ° C., and can store meat and fish for a long time without freezing.

When the food 58 is stored in the hypoxic chamber 100, the food 58 breathes and discharges CO ₂ , so the CO ₂ sensor 72 detects the CO ₂ , and the control unit 70 controls the current collectors 122 and 124. On the other hand, energization is started or the value of the energized current is increased. Thus, power can be saved until the food 58 is stored.

  Further, by providing the water repellent layer 126, water can be prevented from entering the anode layer 118 from the water supply body 128, and only water vapor can be transmitted, so that the flooding phenomenon can be prevented.

  In addition, since a polymer film is used as the water repellent layer 126, even if there is an impurity such as a mineral in the supplied water, a phenomenon that the electrolyte membrane 116 is deteriorated can be prevented by blocking. Further, when the polymer film is used, the water repellent performance is not deteriorated and a long life can be obtained.

  Further, by providing the water repellent layer 130, the water generated in the cathode layer 120 flows to the anode layer 118, whereby pure water can be supplied to the anode layer 118, and the supply amount from the water supply body 128 is reduced. be able to. Furthermore, since water generated in the cathode layer 120 does not return into the oxygen reduction chamber 100, it is possible to prevent the food 58 from being accelerated by being cooled and condensed in the oxygen reduction chamber 100.

  Further, since defrosted water generated from the R-eva 28 is used, it is not necessary for the user to add water to the water supply body 128 at a constant cycle, and the user forgets to add water. Does not promote deterioration. That is, considering the deterioration of the oxygen reduction device 102, the supplied liquid should be close to pure water, and chlorine and minerals promote deterioration in tap water available in any household. On the other hand, defrost water is water formed by cooling water vapor, and although some metal components are dissolved on R EVA 28, impurities are considerably reduced compared with tap water. Deterioration of the device 102 can be prevented. Moreover, by supplying defrost water to the oxygen reduction apparatus 102, it is led to the evaporating dish provided in the machine room 22 to be converted into water vapor by heat, and the amount released can be reduced.

  Further, the oxygen reduction chamber 100 is fixed inside the vegetable chamber 16, and an oxygen reduction device 102 is fixed to the back surface of the oxygen reduction chamber 100. Therefore, even if the door 16a of the vegetable compartment 16 is opened, the oxygen reduction chamber 100 remains fixed. Then, when taking out the food 58 stored with reduced oxygen, the food 58 in the oxygen reduction container 106 can be taken out by opening the door 108. With such a structure, it is not necessary to move the electrical wiring, the water supply pipe 152, and the drain pipe 154 connected to the current collectors 122 and 124 of the oxygen reduction device 102, and the oxygen reduction device 102 and the oxygen reduction chamber The 100 airtight seal structure can be simplified, and the degree of freedom in design is increased.

(9) Modification 1
A first modification of the first embodiment will be described with reference to FIG.

  In the first embodiment, only the cathode layer 120 side is covered with the resin 156. However, in this modified example, all parts and side surfaces between the fixing member 132 and the fixing member 134 are sealed with the resin 156.

  Thereby, there is no inflow of oxygen from other parts, and the oxygen in the oxygen reduction container 106 can be reduced more reliably by the oxygen reduction unit 115.

(10) Modification 2
Next, a second modification of the first embodiment will be described with reference to FIG.

  In the above embodiment, the electric wires 158 and 160 connected to the current collector 122 and the current collector 124 pass through the case 114, but gas cannot enter and exit from this portion.

  However, in this modified example, vents 162 and 164 are provided in a portion through which the electric wire 158 connected to the current collector 122 and the electric wire 160 connected to the current collector 124 penetrate, and the vents 162 and 164 are connected to the electric wires 158, 158, It may be larger than the outer diameter of 160 so that oxygen can diffuse from the vents 162 and 164.

Embodiment 2

  Next, the oxygen reduction apparatus 200 of the refrigerator 10 of Embodiment 2 is demonstrated based on FIGS. The difference between the present embodiment and the first embodiment is an oxygen reduction device 200 and a water supply device 300 that supplies water to the oxygen reduction device 200. Hereinafter, it demonstrates in order.

(1) Oxygen reduction device 200
In the oxygen reduction device 200, an oxygen reduction unit 202 is housed inside a case 204 having heat insulation properties. The oxygen reduction unit 202 will be described with reference to FIGS. 14 is a longitudinal sectional view of the oxygen reduction device 200, FIG. 15 is an exploded perspective view of the oxygen reduction unit 202, and FIG. 16 is an exploded perspective view of the oxygen reduction device 200. In FIGS. 14 to 16, the thickness of each member is thin, but the thickness is enlarged to make the explanation easy to understand. Further, the description of the same members as those in the first embodiment is omitted.

  An electrolyte membrane 206 is provided in the vertical direction, an anode layer 208 is provided at the rear of the electrolyte membrane 206, and a cathode layer 210 is provided at the front of the electrolyte membrane 206. The cathode layer 210 is a laminate of a carbon catalyst and carbon paper. Further, platinum catalyst is supported on the anode layer 208 and the cathode layer 210, respectively. The electrolyte membrane 206, the anode layer 208, and the cathode layer 210 are integrally joined using a hot press or the like. Behind the anode layer 208. A positive current collector 212 is provided, and a negative current collector 214 is provided in front of the cathode layer 210. Both current collectors 212 and 214 have slit-like openings 216 and 218, respectively, through which gas passes. The current collector 212 performs positive energization on the anode layer 208, and the current collector 214 performs negative energization on the cathode layer 210. Both current collectors 212 and 214 are energized from electric wires (not shown). In addition, an insulator 220 is provided between the current collectors 212 and 214 in order to prevent the current collectors 212 and 214 from contacting each other. The insulator 220 has a frame shape, and an electrolyte membrane 206, an anode layer 208, and a cathode layer 210 are accommodated therein.

  A sheet-shaped water supply body 222 is disposed behind the current collector 212 on the anode layer 208 side. As this water supply body 222, it is a nonwoven fabric etc., for example.

  The members stacked in order as described above are sandwiched and fixed by a pair of front and rear rear fixing members 224 and a front fixing member 226. The rear fixing member 224 disposed on the anode side has a storage recess 228 for storing the stacked members, and a groove 230 from which the two current collectors 212 and 214 protrude is provided at the top. In addition, a slit-like opening 232 through which gas passes is opened at the center of the rear fixing member 224.

  The front fixing member 226 attached to the cathode side has a plate shape, and has a slit-like opening 234 through which gas passes in the center. As shown in FIG. 14, the slit-like opening 234 is inclined so as to become narrower as it is later, unlike the cross-sectional area on the front side and the cross-sectional area on the rear side. This is to make it easier to send air to the current collector 214.

  The rear fixing member 224 and the front fixing member 226 are screwed with screws (not shown). A unit in which these members are integrated is referred to as an “oxygen reduction unit 202” in the second embodiment. Two current collectors 212 and 214 protrude from the upper part of the oxygen reduction unit 202, and a water supply body 222 hangs from the lower part.

(2) Case 204
The oxygen reduction unit 202 described above is accommodated inside a case 204 having a box-like heat insulating property. The case 204 will be described with reference to FIGS.

  The case 204 includes a rectangular parallelepiped front case 236, a rear case 238, a front case 236, and a frame-shaped middle case 240 sandwiched between the rear case 238. A front case 236 is arranged on the cathode side of the oxygen reduction unit 202, a rear case 238 is arranged on the anode side, and the front case 236, the rear case 238, and the middle case 240 are not shown in the state in which the oxygen reduction unit 202 is stored. Screwed.

  The front case 236 will be described with reference to FIGS. A square-shaped reaction recess 244 is provided at the center of the rear surface of the front case 236 having heat insulation properties. Further, a groove-shaped upper flow path 246 is provided from the upper surface of the reaction recess 244 toward the upper surface of the front case 236, and an upper vent hole 248 is opened on the upper surface of the front case 236. Further, a groove-like lower flow path 250 is provided downward from the lower surface of the reaction recess 244, and a lower vent hole 252 is opened on the lower surface of the front case 236. As shown in FIG. 14, a rectangular parallelepiped space is generated between the cathode-side current collector 214 and the front wall of the front case 236 by the reaction recess 244. Hereinafter, this space is referred to as “reaction space”.

  Next, the middle case 240 will be described with reference to FIGS. 14 and 16. A front fixing member 226 of the oxygen reduction unit 202 is housed in the central portion 242 of the frame-shaped middle case 240.

  Next, the rear case 238 will be described with reference to FIGS. 16 and 18. A storage recess 254 that can store the rear fixing member 224 of the oxygen reduction unit 202 is provided at the center of the front surface of the rear case 238, and the two current collectors 212 and 214 extend from the storage recess 254 toward the upper surface of the rear case 238. Are provided with grooves 256 and 258 from which. An exhaust recess 260 is further provided on the rear surface of the storage recess 254, and the lower surface of the exhaust recess 260 has an inclined surface so as to approach each other and communicates with the exhaust port 262. The exhaust port 262 opens on the lower surface of the rear case 238.

  The case 204 in which the oxygen reduction unit 202 is stored is attached to the rear surface of the container storage unit 104 of the oxygen reduction chamber 100. This attachment method will be described with reference to FIG.

  At the center of the rear surface of the container storage unit 104, a cubic storage holding unit 264 projects toward the storage side. The storage case 264 stores the front case 236 of the case 204 from the rear. Therefore, the upper hole 266 and the lower hole 268 are opened at positions corresponding to the upper ventilation hole 248 and the lower ventilation hole 252 that are opened on the upper surface and the lower surface of the front case 236.

  Since the case 204 protrudes from the rear surface of the container storage unit 104, the cover 270 is covered so as to cover the protruding portion. The cover 270 is made of a synthetic resin and has a shape that covers the entire rear case 238 of the case 204. The cover 270 is provided with current collector openings 278 and 278 through which the two current collectors 212 and 214 protrude. In addition, an exhaust port 280 communicating with the exhaust port 262 of the rear case 238 is opened.

(3) Water supply device 300
Next, the water supply apparatus 300 is demonstrated based on FIG. 14 and FIG.

  The water supply apparatus 300 has a water supply main body 302, and the water supply main body 302 is a horizontally long rectangular parallelepiped box. The water supply main body 302 is vertically divided by a partition wall 304 inside thereof, and an upper portion constitutes a water purification compartment 306 and a lower portion constitutes a suction section 308. A water supply pipe 152 is connected to the upper surface of the left end portion of the water supply main body 302, that is, the upper surface of the water purification section 306. This water supply pipe 152 is fed with defrosted water generated from the R EVA 28 of the refrigerator 10 by the pump 146.

  As shown in FIG. 18, the partition wall 304 is inclined downward from a portion to which the water supply pipe 152 is connected, and a water supply hole 310 leading to the suction section 308 is formed at the right end portion. A purified water section 312 made of an ion exchange resin is provided inside the purified water section 306. By providing this water purification unit 312, it is possible to remove the influence of the quality of defrost water supplied from the R EVA 28, and to prevent the oxygen reduction unit 115 from deteriorating. That is, the defrost water is frost adhering to the R EVA 28 and is collected in the drain pan, and therefore contains metal ions. Therefore, since there is a possibility of promoting the hydrolysis of the synthetic resin fibers constituting the water supply body 222, the provision of the water purification unit 312 can remove the influence of the quality of the defrost water.

  The suction section 308 has a water storage part 314 for storing the water supplied from the water supply hole 310. Further, a drain pipe 154 is provided at the left end of the suction section 308. A partition wall 316 is provided between the drain pipe 154 and the water storage unit 314. The defrost water supplied from the water supply hole 310 is accumulated in the water storage unit 314. The water storage unit 314 is recessed at the center, and the lower part of the water supply body 222 of the oxygen reduction unit 202 described above is immersed, and the water supply body 222 sucks up the accumulated water. When the amount of water in the water storage unit 314 increases and exceeds the partition wall 316, the water is drained from the drain pipe 154 to an evaporating dish (not shown). In the water supply main body 302 that is a horizontally long rectangular parallelepiped, the suction section 308 projects forward from the water purification section 306, and the water supply body 222 projects from the ceiling surface that projects forward from the suction section 308.

(4) Operation State of Oxygen Reduction Device 200 The operation state of the oxygen reduction device 200 will be described with reference to FIGS.

  The oxygen reduction device 200 is supplied from the water supply device 300 to the water supply body 222 in the same manner as the oxygen reduction device 102 of the first embodiment, and the water supplied to the water supply body 222 is expressed by Expression (1) and Expression (2). Due to the reduced oxygen reaction, the oxygen reduction chamber 100 is reduced in oxygen.

  By the way, the hypoxic reaction is exothermic, and the higher the temperature, the more efficient the catalyst, and the reaction proceeds at a lower voltage. On the other hand, if the oxygen reduction device is entirely covered with the heat insulating material, contact with air is lost and the oxygen reduction reaction is stopped. Further, in a structure in which air does not move, water generated in the cathode layer accumulates in the vicinity thereof, causing a flooding phenomenon that hinders contact with air.

  Therefore, first, in this embodiment, the oxygen reduction unit 202 is covered with a heat insulating case 204, the temperature generated by the oxygen reduction reaction is maintained, the efficiency of the catalyst is improved, and the reaction is performed at a lower voltage. In particular, since the portion of the cathode layer 210 is entirely covered by the front wall of the front case 236, heat insulation can be further maintained.

  Second, in the present embodiment, even if the heat insulation as described above is maintained, a reaction space is formed by the reaction recess 244 on the cathode layer 210 side, and in this reaction space, the upper vent 248 of the front case 236 and Air is supplied from the lower vent hole 252. In other words, oxygen-containing air is supplied from the lower hole 268 to the reaction space formed by the reaction concave portion 244 through the lower vent hole 252 and the lower flow path 250, and the oxygen reduction represented by the expressions (1) and (2). The reaction can be promoted.

  Thirdly, in the present embodiment, water generated by the oxygen reduction reaction is converted into water vapor by the heat generation, and is discharged from the reaction space into the oxygen reduction container 106 through the upper flow path 246, the upper ventilation hole 248, and the upper hole 266. The Therefore, no flooding phenomenon occurs. In particular, since the surrounding air is warmed by the heat generation of the oxygen reduction unit 202, the air easily escapes from above into the upper vent hole 248, and the water vapor generated by the oxygen reduction reaction also easily escapes.

  Fourthly, in this embodiment, by providing the vent holes 248 and 252 above and below the reaction space, the flow of air from the bottom to the top becomes smooth, and air enters from the bottom to warm the oxygen reduction unit 202. Thus, it is possible to create an updraft in which the air containing water vapor generated here is discharged upward.

  In order to prove the above contents, the oxygen reduction unit housed in a case without heat insulation, the oxygen reduction unit 115 of the first embodiment, the cathode central temperature, the anode central temperature, both current collectors in the oxygen reduction unit 202 of the present embodiment. The input voltage applied to the body was tested and measured. The results are shown in the table of FIG.

  According to this experiment, the oxygen reduction units 115 and 202 of Embodiment 1 and Embodiment 2 housed in a case with heat insulation can maintain a higher temperature than the conventional example housed in a case without heat insulation.

  Further, in the second embodiment, the input voltage can be made lower than that in the first embodiment, thereby saving energy.

(5) Effect According to the present embodiment, since the oxygen reduction unit 202 is covered with the heat insulating case 204, the temperature can be increased by the heat generated by the oxygen reduction reaction of the oxygen reduction unit 202, and the catalyst functions more. Can be raised. In addition, since the front of the cathode layer 210 is covered by the front case 236 and a reaction space is formed by the reaction recess 244, the cathode layer 210 can come into contact with air, and the efficiency of the catalyst by heat insulation due to the covering. Can be raised.

  The front case 236 has an upper air hole 248 and a lower air hole 252 that are open to communicate with the reaction space, so that the air flow is smooth and oxygen-containing air is easily supplied to the cathode layer 210. In particular, since a plurality of air holes 236 and 238 are provided, air circulation can be ensured.

  Further, since the upper vent hole 248 and the lower vent hole 252 communicate with the inside of the oxygen reduction chamber 100, the air inside the oxygen reduction chamber 100 can be reliably supplied.

  In addition, since the cross-sectional areas of the upper ventilation hole 248 and the lower ventilation hole 252 are smaller than the area of the plurality of openings 234 opened in the front fixing member 226, air can be circulated reliably, and the cathode layer 210 has air flow. Can supply.

  In addition, since the width in the left-right direction of the front fixing member 226 of the oxygen reduction unit 202 is wider than the reaction recess 244, air can be easily supplied. Furthermore, since the width of the reaction recess 244 is wider than the width of the upper flow path 246 and the lower flow path 250, air easily diffuses inside the reaction recess 244.

  In addition, the strip-shaped opening 234 of the front fixing member 226 is inclined so as to become narrower later, unlike the cross-sectional area on the front side and the cross-sectional area on the rear side. easy.

  Further, in the upper flow path 246 inside the front case 236, the water vapor discharged upward by the ascending airflow decreases from the oxygen reduction unit 202, and as a result, the temperature drops, so that water droplets form inside the front case 236 and cause condensation. Sometimes. However, even if such condensation occurs, the upper flow path 246 and the lower flow path 250 are formed in a straight line, so that they do not collect in the reaction recess 244 of the oxygen reduction unit 202 and flow out of the lower vent hole 252 and are discharged. Is done.

(6) Modification 1
In the first modification, as shown in FIG. 21, the lower surface that continues from the storage recess 254 to the lower flow path 250 is an inclined surface. As a result, water droplets due to condensation generated in the upper flow path 246 and the reaction recess 244 flow more reliably to the lower flow path 250.

(7) Modification 2
In the second modification, as shown in FIG. 22, an upper flow path 246 and a lower flow path 250 are provided at positions slightly apart from the front case 236 that is in contact with the oxygen reduction unit 202. Thereby, the oxygen reduction unit 202 can be more reliably covered with the front case 236 having heat insulation properties, and the heat insulation effect can be enhanced. Therefore, the efficiency of the catalyst can be further increased.

(8) Modification 3
In Modification 3, as shown in FIG. 23, a plurality of ribs 282 are provided in the lower flow path 250 provided in the front case 236. These ribs 282 are provided at different levels and inclined, and the air that has entered through the lower vent holes 252 is disturbed by the ribs 282, and can be spread throughout the reaction recesses 244. The catalyst can be reacted more efficiently.

(9) Modification 4
In the modified example 4, as shown in FIG. 24, the upper flow path 246 and the lower flow path 250 are shifted and arranged so as not to be in a straight line. With such an arrangement, turbulence of the airflow occurs, and air can be distributed throughout the oxygen reduction unit 202.

(10) Modification 5
In the second embodiment, the vent holes communicating with the reaction space are provided on the upper and lower sides.

Example of change

  In each said embodiment, although the oxygen reduction unit was provided in the refrigerator 10, you may provide in the apparatus inside other than this. In other words, it can be applied to commercial and household refrigerators that can preserve vegetables, foods, etc. in a high-quality state for a long time, and can store chemicals, medical materials, chemical substances, etc. that are sensitive to oxygen concentration. Applicable to refrigerators and the like.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 10 ... Refrigerator, 14 ... Cold room, 16 ... Vegetable room, 28 ... R Eva, 44 ... Chilled room, 48 ... Vegetable container, 70 ... Control part, 100 * ..Oxygen reduction chamber, 102... Oxygen reduction device, 104... Container housing unit, 106... Oxygen reduction container, 108. 116 ... electrolyte membrane, 118 ... anode layer, 120 ... cathode layer, 122 ... current collector, 124 ... current collector, 126 ... water-repellent layer, 128 ... water supply 130, water repellent layer, 132, fixing member, 134, fixing member, 136, exhaust port, 138, opening, 140, unit housing, 156, body Resin, 158 ... Electric wire, 160 ... Electric wire, 162 ... Vent, 164 ... Vent

Claims (14)

In the oxygen reduction device that reduces oxygen in the oxygen reduction chamber,
A polymer electrolyte membrane;
An anode layer provided on one side of the polymer electrolyte membrane;
A cathode layer provided on the other side of the polymer electrolyte membrane and leading to the oxygen reduction chamber;
A positive current collector for energizing the anode layer;
A negative current collector for energizing the cathode layer;
A water supply section provided on the anode layer side;
A hypoxic unit is housed inside a heat-insulating case,
The wall of the case covers the cathode surface of the oxygen reduction unit on the cathode layer side,
A reaction space is formed between the wall of the case and the cathode surface of the oxygen reduction unit ,
The case has an exhaust port for diffusing oxygen generated in the oxygen reduction device,
The exhaust port opens below the polymer electrolyte membrane,
Hypoxic device. A vent hole opens at the peripheral edge of the case,
The vent is in communication with the reaction space via a flow path;
The oxygen reduction device according to claim 1. A plurality of the air holes are opened at the peripheral edge of the case.
The oxygen-reducing device according to claim 2. The portion of the case where the vent hole is open is disposed in the oxygen-reducing chamber,
The vent is open facing the oxygen-reducing chamber,
The oxygen reduction device according to claim 2 or 3. The oxygen reduction unit includes a fixing member that integrally holds the water supply body, the positive current collector, the anode layer, the polymer electrolyte membrane, the cathode layer, and the negative current collector. ,
On the cathode surface side of the fixing member, an opening for allowing gas to pass is opened,
The cross-sectional area of the vent is smaller than the opening,
The oxygen reduction device according to any one of claims 2 to 4. The width of the reaction space is greater than the width of the flow path;
The oxygen reduction device according to any one of claims 2 to 5. Upper and lower ventilation holes are opened on the upper and lower surfaces of the case, respectively.
The upper vent communicates with the reaction space via an upper flow path;
The lower vent communicates with the reaction space via a lower flow path;
The oxygen reduction device according to claim 3. The upper flow path and the lower flow path are arranged in a straight line,
The oxygen reduction device according to claim 7. The lower surface following the lower flow path from the reaction concave portion constituting the reaction space is formed to be inclined,
The oxygen-reducing device according to claim 7 or 8. The upper flow path and the lower flow path are separated from the oxygen reduction unit,
The oxygen reduction device according to claim 7. Ribs are provided in the lower flow path,
The oxygen reduction device according to claim 7. Electric wires for energizing the current collectors respectively penetrate the case,
A vent larger than the outer diameter of the electric wire is provided in each penetrating part,
The oxygen reduction device according to claim 1 . A water holding part for storing water used in the oxygen reduction device inside the case;
The oxygen-reducing device according to any one of claims 1 to 12 . The oxygen reduction chamber and the oxygen reduction device are provided inside a refrigerator.
The oxygen reduction device according to any one of claims 1 to 13 .

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