JP2015145783A - refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the reduction in the freshness of food items by making effective use of carbon dioxide produced in a photocatalytic reaction.SOLUTION: A glass member 70 in which a photocatalyst layer 71 is formed is attached, via a seal member 72, to a ceiling 42 of a decompression storage chamber 24 provided in a cold room of a refrigerator. A light source 80 is disposed above the glass member 70 via a small clearance. When an LED 83 of the light source 80 is turned on, light from the LED 83 is transmitted by the glass member 70 and incident on the photocatalyst layer 71. As a result, the photocatalyst layer 71 produces radicals from water or the like and the radicals decompose gas or the like from a food item into carbon dioxide and water. Increasing the carbon dioxide concentration of the storage chamber 24 suppresses the respiration of vegetables, suppresses enzyme reactions of meat and fish, and further suppresses proliferation of microorganisms.

Description

  The present invention relates to a refrigerator and a food storage method.

  Refrigerators that utilize the redox action of photocatalysts have been known. In the first prior art, a photocatalytic device is attached to the side surface of a refrigerator (Patent Document 1). The first prior art photocatalyst device carries a photocatalyst comprising a thin film of titanium dioxide, has a base having a photocatalytic reaction surface, a light emitting diode element (hereinafter referred to as “light emitting diode”) that emits predetermined visible light, is arranged so that the catalyst can be illuminated LED). The LED mainly emits visible light (light having a wavelength of 400 nm to 800 nm) and ultraviolet light (light having a wavelength of 360 to 400 nm) such as blue, green, and red. In the second prior art, titanium oxide fine particles including rutile type on which ultrafine metal particles such as platinum having a particle diameter of 10 nm or less are supported are used as the main component of the photocatalytic film (Patent Document 2). The main component and the binder component are provided on the substrate to form a photocatalytic film. In the second prior art, the photocatalytic film is irradiated with light having a wavelength of 360 to 410 nm from the LED. In the third prior art, the inside of a refrigerator is deodorized using a honeycomb filter provided with a photocatalyst (Patent Document 3). In the third prior art, decomposition of methyl mercaptan and dimethyl disulfide is promoted by using both a photocatalyst that reacts with visible light and an oxidation catalyst as photocatalysts. In the fourth prior art, when the temperature in the storage chamber reaches a predetermined temperature range, the LED is irradiated with ultraviolet rays (Patent Document 4).

Japanese Patent Laid-Open No. 9-941 JP 2003-290664 A JP 2006-17358 A JP 2007-3021 A

  In the photocatalytic reaction, the odor component gas and bacteria are decomposed into carbon dioxide and water. The prior art is satisfied only by decomposing odor component gas and various germs, and does not consider the effective use of carbon dioxide, which is a decomposition product.

  Therefore, an object of the present invention is to provide a refrigerator and a food storage method that can be used for food preservation by increasing carbon dioxide in a storage chamber having a sealed structure. A further object of the present invention is to cause a photocatalytic reaction in a closed storage chamber, thereby increasing the carbon dioxide concentration in the storage chamber, and the carbon dioxide can suppress a decrease in freshness of food in the storage chamber. It is to provide a food preservation method.

  In order to solve the above problems, a refrigerator according to the present invention includes a storage chamber for storing food, the storage chamber has a sealed structure, and a carbon dioxide increasing device for increasing carbon dioxide in the storage chamber. Is provided.

  The carbon dioxide increasing device may be configured to generate carbon dioxide by decomposing food gas generated from the food stored in the storage chamber.

  The carbon dioxide increasing device may include a light source and a photocatalyst that generates carbon dioxide from food gas by using energy of light incident from the light source.

  You may provide the light-shielding member for suppressing that the light ray output from a light source is irradiated to the foodstuff in a storage chamber.

  A pressure reducing device for reducing the pressure in the storage chamber may be provided.

  The carbon dioxide increasing device may be operated after the pressure in the storage chamber is reduced to a predetermined pressure by the decompression device.

It is sectional drawing of the refrigerator which concerns on embodiment of this invention. It is sectional drawing of the decompression storage room which concerns on 1st Example. It is an assembly perspective view of a decompression storage room. It is a side view which shows the state before attaching an LED cover to a decompression storage chamber. It is a side view which shows a mode that an LED cover is attached to a decompression storage chamber. It is a side view which shows a mode that the LED cover was attached to the decompression storage chamber. It is an enlarged view which shows the state which attaches an LED cover to a decompression storage chamber. It is an enlarged view which shows the state which attached the LED cover to the decompression storage chamber. It is a top view of the decompression storage room of the state where the LED cover was attached. The enlarged side view which shows the state before attaching an LED board to a LED cover. The enlarged side view which shows the state which inserted the LED board in the LED cover. The enlarged side view which shows the state which attached the LED board to the LED cover. The perspective view which looked at the LED cover before LED board attachment from the back side. The perspective view which looked at the LED cover in which the LED board was inserted from the back side. The perspective view which looked at the LED cover with which the LED board was attached from the back side. The perspective view and sectional drawing of the packing attached to the circumference | surroundings of the glass substrate in which the photocatalyst was formed. The expanded sectional view which shows the state of packing before attaching a glass substrate. The expanded sectional view which shows the mode of packing when a glass substrate is attached. The expanded sectional view which shows the mode of packing when an LED cover is attached on a glass substrate. The flowchart of the process which shows control of the pressure of a pressure reduction storage chamber, and control of a light source. Explanatory drawing which shows a mode that the carbon dioxide in a pressure-reduction storage chamber increases by photocatalytic reaction, and the freshness fall of a foodstuff is suppressed. The graph of the experiment which confirmed that the density | concentration change of a carbon dioxide and ethylene gas differed by the presence or absence of a photocatalytic reaction when avocado was accommodated in the decompression storage chamber. The graph of the experiment which confirmed that the density | concentration change of a carbon dioxide and an odor component gas differed by the presence or absence of a photocatalytic reaction when meat or fish was accommodated in the decompression storage room. The graph of the experiment which confirmed that the change of the vitamin C residual amount of the spinach accommodated in the decompression storage room differed with the presence or absence of a photocatalytic reaction. The graph of the experiment which confirmed that the change of the vitamin C residual amount of the broccoli accommodated in the decompression storage room differed with the presence or absence of a photocatalytic reaction. The graph of the experiment which confirmed that the change of K value of the fillet of the tuna accommodated in the decompression storage room differed with the presence or absence of a photocatalytic reaction. The graph of the experiment which confirmed that the change of the redness of the beef accommodated in the vacuum storage room differed with the presence or absence of a photocatalytic reaction. It is sectional drawing of the decompression storage room which concerns on 2nd Example. It is sectional drawing of the refrigerator which concerns on 3rd Example. The structure of the apparatus for increasing a carbon dioxide concerning 4th Example is shown. A state in which the carbon dioxide increasing device is used in a closed container such as a cooler box is shown. It is sectional drawing which concerns on 4th Example and shows the structure electrically fed to the carbon dioxide increase apparatus attached in the airtight container from the solar power generation device provided in the exterior of the airtight container.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, as will be described in detail below, food is stored in a sealed storage room, and the carbon dioxide in the storage room is increased using the food, and a decrease in freshness of the food is suppressed by the carbon dioxide.

  As an example of a method for increasing carbon dioxide, a photocatalytic reaction can be used. In the photocatalytic reaction, radicals with very high reactivity are generated by decomposing oxygen, hydrogen, and moisture in the air, and the odor component gas is decomposed and germs are removed by the radicals. In a sealed storage room, the moisture of the food becomes a raw material for radicals, and the radicals derived from the moisture of the food decompose and remove the odor component gas. Moisture from food is not only a raw material for radicals, but is also confined in a sealed storage room, creating a high humidity environment. Therefore, it can suppress that a foodstuff dries and a flavor is impaired.

  Furthermore, the oxidation-reduction reaction by the photocatalytic reaction finally decomposes the odor component gas and various bacteria into carbon dioxide and water. The decomposition products, carbon dioxide and water, are trapped in a sealed storage chamber. Moisture, which is one of the decomposition products, is reused as a raw material for radicals and helps maintain a high humidity environment. Carbon dioxide, which is the other decomposition product, suppresses the enzymatic reaction of meat and fish, reduces the respiratory action of vegetables, prevents deterioration, and suppresses the growth of microorganisms.

  By storing the food in a sealed storage room and carrying out the photocatalytic reaction, the odorous component gas and moisture from the food can be used as a raw material for radicals, and carbon dioxide, which is a decomposition product of the photocatalytic reaction, is used for the freshness of the food. It can be actively used for holding. In this way, the primary effect (decomposition and sterilization of odor component gas) by the photocatalytic reaction and the secondary effect by carbon dioxide, which is a product of the photocatalytic reaction, are generated in the sealed storage chamber. It can be made to suppress that the freshness of food falls.

  Therefore, in this embodiment, in a refrigerator including a storage chamber 24 that is sealed when food is stored, ultraviolet light is applied to members inside the sealed storage chamber 24 in the refrigerator or other members constituting the storage chamber 24. Alternatively, a visible light responsive photocatalyst 71 is provided. Further, a light source for irradiating the photocatalyst 71 with visible light or ultraviolet light is provided in the storage chamber 24 or the member 20 outside the storage chamber 24.

  If the storage chamber 24 is kept in a state lower than the atmospheric pressure, the carbon dioxide concentration in the storage chamber 24 can be made higher than the carbon dioxide concentration in the normal atmosphere. Thereby, the secondary effect by a carbon dioxide can be exhibited.

  Hereinafter, the refrigerator of one Embodiment of this invention is demonstrated using figures. FIG. 1 is a central longitudinal sectional view of the refrigerator of the present embodiment. FIG. 2 is a cross-sectional view of the lowermost space portion of the refrigerator compartment 2. FIG. 3 is a perspective view of the decompression storage chamber 24.

  The refrigerator includes a box-shaped refrigerator main body 1 and a plurality of doors 6 to 9 attached to the opening of the refrigerator main body 1 so as to be openable and closable. The refrigerator body 1 includes a steel plate outer box 11, a resin inner box 12, a urethane foam heat insulating material 13 and a vacuum heat insulating material (not shown) provided between the outer box 11 and the inner box 12. Configured. The refrigerator body 1 is provided with a plurality of storage rooms in the order of the refrigerator compartment 2, the freezer compartments 3 and 4, and the vegetable compartment 5 from the top. In other words, the refrigerator compartment 2 is arranged at the uppermost stage, and the vegetable compartment 5 is arranged at the lowermost stage, and between the refrigerator compartment 2 and the vegetable compartment 5, the two rooms are insulated from each other. Partitioned freezer compartments 3 and 4 are provided. The refrigerator compartment 2 and the vegetable compartment 5 are storage compartments (for example, about 5 ° C.) in a refrigerated temperature zone. The freezing rooms 3 and 4 are storage rooms in a freezing temperature range of 0 ° C. or lower (for example, a temperature range of about −20 ° C. to −18 ° C.). These storage chambers 2 to 5 are partitioned by partition walls 33, 34, and 35.

  On the front surface of the refrigerator body 1, doors 6 to 9 that close the front opening portions of the storage chambers 2 to 5 are provided. The refrigerator compartment door 6 closes the front opening of the refrigerator compartment 2, the freezer compartment door 7 closes the front opening of the freezer compartment 3, and the freezer compartment door 8 closes the front opening of the freezer compartment 4. The vegetable compartment door 9 is a door that closes the front opening of the vegetable compartment 5. The refrigerator compartment door 6 is configured as a double door with double doors. The freezer compartment door 7, the freezer compartment door 8, and the vegetable compartment door 9 are configured as drawer-type doors, and the containers in the storage compartment are drawn out together with the drawer doors.

  The refrigerator body 1 is provided with a refrigeration cycle. This refrigeration cycle is configured by connecting a compressor 14, a condenser (not shown), a capillary tube (not shown) and an evaporator 15, and then the compressor 14 again. The compressor 14 and the condenser are installed in a machine room provided at the lower back of the refrigerator body 1. The evaporator 15 is installed in a cooler chamber provided behind the freezing chambers 3 and 4. A blower fan 16 is installed above the evaporator 15.

  The cold air cooled by the evaporator 15 is sent to the storage rooms of the refrigerator compartment 2, the freezer compartments 3, 4 and the vegetable compartment 5 by the blower fan 16. Specifically, a part of the cold air sent by the blower fan 16 is sent to a storage room (refrigeration room 2 and vegetable room 5) in a refrigeration temperature zone via a damper device (not shown) that can be opened and closed. . The other part of the cold air is sent to a storage room (freezing room 3, 4) in the freezing temperature zone.

  The cool air sent to the storage rooms of the refrigerator compartment 2, the freezer compartments 3, 4 and the vegetable compartment 5 by the blower fan 16 cools the storage compartments 2 to 5, and then returns to the cooler compartment through the cool air return passage. It is. Thus, the refrigerator of this embodiment has a cold air circulation structure, and maintains each of the storage chambers 2 to 5 at an appropriate temperature.

  A plurality of shelves 17 to 20 made of a transparent resin plate are detachably installed in the refrigerator compartment 2. The lowermost shelf 20 is installed in contact with the back surface and both side surfaces of the inner box 12, and divides the lowermost space 21, which is the lower space, from the upper space. A plurality of door pockets 25 to 27 are installed inside the left and right refrigerator compartment doors 6. These door pockets 25 to 27 are provided so as to protrude into the refrigerator compartment 2 with the refrigerator compartment door 6 being closed. A back panel 30 that forms a passage through which the cool air supplied from the blower fan 16 passes is provided on the back of the refrigerator compartment 2.

  In the lowermost space 21, in order from the left, an ice making water tank (not shown) for supplying ice making water to an ice tray in the freezer compartment 3, and a storage case (not shown) for storing food such as desserts. And the decompression storage room 24 for depressurizing the inside of the room and maintaining the freshness of food and storing it for a long period of time is installed. The decompression storage chamber 24 has a width that is narrower than the width of the refrigerator compartment 2, and is disposed adjacent to the side surface of the refrigerator compartment 2.

  An ice making water tank and a storage case (not shown) are disposed behind the refrigerator compartment door 6 on the left side. Thereby, the user can pull out the ice making water tank and the storage case only by opening the left refrigerator door 6. The decompression storage chamber 24 is disposed behind the refrigerator door 6 on the right side. Thereby, the user can pull out the food tray 60 of the decompression storage chamber 24 only by opening the right refrigerator compartment door 6.

  The ice making water tank and the storage case are located behind the lowermost door pocket 27 of the left refrigerator door 6. The decompression storage chamber 24 is positioned behind the lowermost door pocket 27 of the right refrigeration chamber door 6. The cold air cooled by the evaporator 15 and sent to the refrigerator compartment 2 passes through the periphery of the decompression storage chamber 24 to indirectly cool the inside of the decompression storage chamber 24. Note that the arrangement of the ice making water tank, the storage case, and the decompression storage chamber 24 is not limited to this. For example, the construction for increasing the size of the decompression storage chamber 24 by omitting the storage case and the ice making water tank are different. The structure arrange | positioned in a place may be sufficient.

  An ice making water pump (not shown) is installed behind the ice making water tank. A negative pressure pump 29, which is an example of a decompression device for decompressing the decompression storage chamber 24, is disposed in the space behind the storage case and at the rear side of the decompression storage chamber 24. As shown in FIG. 3, the negative pressure pump 29 is connected to a pump connection portion provided on the side surface of the decompression storage chamber 24 via a conduit 29 </ b> A. A pressure sensor 28 is provided in the middle of the conduit 29A.

  The controller 90 controls the operation of the decompression storage chamber 24. The controller 90 may be configured as a part of a controller that controls the entire refrigerator. The controller 90 controls the operation of the negative pressure pump 29 based on the pressure value in the decompression storage chamber 24 detected by the pressure sensor 28.

  The controller 90 includes a door switch 91 for detecting the open / closed state of the door 6 in the refrigerator compartment 2, a door switch 92 for detecting the open / closed state of the door 50 (see FIG. 3) of the decompression storage chamber 24, A food gas sensor 93 that detects the concentration of food gas in the storage chamber 24 is connected. As will be described later, in the controller 90, the door 6 of the refrigerator compartment 2 and the door 50 (see FIG. 3) of the decompression storage chamber 24 are closed, and the pressure in the decompression storage chamber 24 is reduced to a predetermined value. Further, after confirming that the concentration of the food gas in the decompression storage chamber 24 has reached a predetermined value or more, a control signal is output to the light source 80 to light it.

  As shown in FIGS. 2 and 3, the decompression storage chamber 24 includes a box-shaped decompression storage chamber main body 40 having a food in / out opening, and a decompression storage chamber for opening and closing the food in / out opening of the decompression storage main body 40. A door 50 and a food tray 60 for storing food and taking it in and out of the decompression storage chamber door 50 are provided. By operating the handle 51 of the decompression storage chamber door 50, the user can open the food take-out opening, pull out the food tray 60, and put food in and out of the food tray 60. Specifically, when the user pulls the decompression storage chamber door 50 toward the front, a pressure release valve provided in a part of the decompression storage chamber door 50 operates to release the decompression state of the decompression storage chamber 24, and It becomes a state. As a result, the user can easily open the decompression storage chamber door 50 and put food in and out of the food tray 60.

  The food tray 60 is provided in contact with the bottom 43 of the decompression storage chamber main body 40 so as to be movable back and forth. The food tray 60 is attached to the back side of the decompression storage chamber door 50 and moves back and forth as the decompression storage chamber door 50 moves. When the user places food on the food tray 60 and closes the decompression storage chamber door 50, the inside of the decompression storage chamber 24 is in a sealed state. When the door 50 is closed, the door switch 91 is turned on, the negative pressure pump 29 is driven, and the decompression storage chamber 24 is decompressed to a state lower than the atmospheric pressure. Thereby, the oxygen concentration in the decompression storage chamber 24 falls, and deterioration of the nutrient component in a foodstuff can be prevented. In addition, since it is common to close the door 6 of the refrigerator compartment 2 after closing the decompression storage chamber door 50, the structure which abbreviate | omits the door switch 92 of the decompression storage chamber 24 may be sufficient. That is, the open / close state of the decompression storage chamber 24 may be indirectly determined by the door switch 91 of the refrigerator compartment 2.

  Furthermore, in this embodiment, the odor component gas and ethylene gas generated from the food stored in the reduced pressure storage chamber 24 are changed to carbon dioxide by the photocatalytic reaction described later. Therefore, in addition to the above-described effect due to the reduced pressure, a freshness maintaining effect due to a change in the gas component in the reduced-pressure storage chamber 24 can be expected. Further, when the decompressed storage chamber 24 in a sealed state is decompressed, moisture slightly evaporates from the food stored in the decompression storage chamber 24. Due to the evaporated water, the inside of the decompression storage chamber 24 becomes in a high humidity state (for example, near 100% humidity). Further, the water evaporated from the food is also used as a radical raw material.

  A glass member 70 as an example of a transparent window portion is attached to the upper portion of the decompression storage chamber 24 via a seal member 72. That is, for example, a rectangular opening is formed in the ceiling portion 42 of the decompression storage chamber body 40, and the rectangular glass member 70 is attached to the opening via the seal member 72. The seal member 72 fills the gap between the peripheral edge of the glass member 70 and the opening, and maintains the hermeticity of the decompression storage chamber 24. Although the decompression storage chamber body 40 bends during decompression, even in that case, no gap is generated around the glass member 70.

  As shown in FIG. 2, a photocatalyst layer 71 is formed on the inner side surface of the glass member 70 located inside the decompression storage chamber 24. In FIG. 2, the thickness of the photocatalyst layer 71 is exaggerated for the sake of understanding.

  A light source 80 is provided outside the decompression storage chamber 24 and positioned above the glass member 70. It is desirable to arrange the light source 80 and the glass member 70 as close as possible. This is because the amount of light that passes through the glass member 70 and reaches the photocatalyst layer 71 can be increased. As the distance between the light source 80 and the glass member 70 increases, the output of the light source 80 needs to be increased. Since light having a short wavelength such as ultraviolet rays is easily attenuated, it is preferable that the distance between the light source 80 and the glass member 70 (more precisely, the photocatalyst layer 71 formed on the glass member 70) is short.

  By the way, various methods of attaching the light source 80 to the refrigerator body 1 are conceivable. Among them, as the first method, for example, as shown in FIG. 2, a method of installing a light source 80 on the lower surface of the lowermost shelf 20 is conceivable. Since the lower surface of the lowermost shelf 20 is close to the ceiling portion 42 of the decompression storage chamber body 40, the amount of light absorbed by the photocatalyst layer 71 can be increased by providing a light source 80 there.

  In the second method of attaching the light source 80 to the refrigerator main body 1, for example, as shown in FIG. 3, the light source 80 is configured as a light source unit that can be attached to and detached from the ceiling portion 42 of the decompression storage chamber main body 40. The light source unit (light source 80) is positioned above the glass member 70 and is detachably attached to the ceiling portion 42.

  Either the first method or the second method may be adopted. In the second method, the glass member 70 having the photocatalyst layer 71 and the light source 80 can be integrally provided in the decompression storage chamber 24. In this embodiment, FIG. 2 shows the light source 80 according to the first method, and FIGS. 3 to 19 show the light source 80 according to the second method. Note that the glass member 70 having the photocatalyst layer 71 and the light source 80 may be disposed at the bottom of the decompression storage chamber 24 as in an embodiment described later.

  In the first method shown in FIG. 2, the light source 80 can be composed of, for example, an LED (Light Emitting Diode) substrate 82 and one or a plurality of LEDs 83 provided on the lower surface side of the LED substrate 82. The LED board 82 having the LEDs 83 can be detachably attached to the lower surface of the shelf 20.

  In the second method shown in FIG. 3, the light source 80 includes an LED substrate 82 (see FIG. 13) on which an LED 83 is provided on the lower surface, and an LED cover 81 for attaching the LED substrate 82 to the ceiling portion 42 of the decompression storage chamber body 40. It can consist of. The LED cover 81 also has a function of protecting the LED substrate 82.

  Here, the wavelength of light emitted from the light source 80 will be examined. The light can be divided into, for example, ultraviolet rays (10 to 400 nm), visible rays (400 to 800 nm), and infrared rays (800 to 4 μm).

  When the photocatalyst layer 71 is composed of an ultraviolet light-responsive catalyst that reacts strongly with ultraviolet light, the light source 80 is also composed of an LED that emits ultraviolet light. When using ultraviolet rays, it is necessary to provide a member for preventing the user from directly viewing the light source 80. The on / off of the light source 80 can also be controlled in conjunction with the door switch 91 of the refrigerator compartment 2 or the switch 92 that detects the operation of the handle 51. However, as a precaution, it is preferable to provide a direct-view prevention member for preventing the ultraviolet rays from being directly viewed by the user. On the other hand, when the photocatalyst layer 71 is composed of a visible light responsive catalyst that reacts strongly with visible light, and the light source 80 is composed of LEDs that emit visible light, the above-mentioned direct-view prevention member is not necessary. Therefore, it is simpler to use the visible light responsive photocatalyst layer 71 and the light source 80 that outputs visible light. Further, when the photocatalytic reaction is caused by visible light, it is not necessary to provide the above members in the space in the refrigerator body 1 or the space in the decompression storage chamber 24, and the capacity of these spaces is not reduced.

  By the way, ultraviolet rays have higher energy than visible rays. Even ultraviolet rays with a relatively long wavelength of 350 nm have energy of 343 kj / mol. The carbon-carbon bond C—C forming the resin constituting the decompression storage chamber 24 is 353 kj / mol. Therefore, when UV rays are irradiated to the resin, a chemical reaction occurs, and the polymer chain may be cut, or the cut part may be bonded to another place of carbon to crosslink and the resin may deteriorate. There is. In particular, since the decompression storage chamber 24 requires a sealed structure that can withstand decompression, it is not preferable that the resin be deteriorated by ultraviolet rays.

  Therefore, in this embodiment, the photocatalytic reaction is obtained using the visible light responsive photocatalyst layer 71 and the light source 80 that emits visible light. Of the visible light wavelength range, visible light having a wavelength near 470 nm, which is relatively strong, is used as an example. Since the LED has advantageous features in terms of life and luminous efficiency, in this embodiment, the light source 80 is composed of the LED. However, the present invention is not limited to this, and other types of light emitting elements may be used.

  As a visible light responsive photocatalyst, for example, a product obtained by processing titanium oxide so as to react to the visible light region is known. Not limited to this, tungsten oxide may be used. Since tungsten oxide reacts only with visible light and does not react with ultraviolet light, relatively high reaction efficiency can be obtained by using tungsten oxide as a photocatalyst. Since tungsten oxide does not need to be processed like titanium oxide, its handling is easy and the cost for forming it on the glass member 70 can be reduced. Also in this respect, it is advantageous to use tungsten oxide as a photocatalyst.

  When the photocatalytic layer 71 is formed from tungsten oxide, the above advantages can be obtained. However, nevertheless, the photocatalytic layer 71 may be formed from titanium oxide or the like, or other substance that reacts to visible light. In addition, a configuration using ultraviolet light may be adopted as long as a disadvantage in obtaining a photocatalytic reaction using ultraviolet light can be tolerated.

  The substrate (carrier) on which the photocatalyst layer 71 is formed is preferably capable of supporting the photocatalyst and transparent to the light beam that causes the photocatalytic reaction. Therefore, the substrate is preferably made of glass or resin that is transparent to visible light.

  However, since the resin is an organic substance, application of a photocatalyst directly causes deterioration of the resin. When a substrate is formed from a resin, primer treatment is required. On the other hand, since glass is an inorganic substance, it does not deteriorate even when applied directly. Therefore, the substrate carrying the photocatalyst layer 71 is preferably formed from glass in terms of the number of manufacturing steps of the substrate, material cost, and the like. However, the structure which forms a transparent protective layer by performing a primer process on the surface of a resin board, and forms the photocatalyst layer 71 on a protective layer may be sufficient.

  By the way, as the thickness dimension of the photocatalyst layer 71 is larger, the effect of the photocatalytic reaction can be enhanced. However, when the thickness dimension is too large, the transparency is lowered. Accordingly, the amount of light transmitted through the photocatalyst layer 71 is reduced. Thereby, when visible light is used as illumination in the decompression storage chamber 24, the visibility of the decompression storage chamber 24 becomes low due to insufficient light quantity. If the photocatalyst layer 71 becomes too thick, the photocatalyst layer 71 may break. Therefore, in this embodiment, the thickness of the photocatalyst layer 71 is set so that the amount of transmitted light does not decrease so much and the possibility of physical destruction decreases.

  As described above, the visible light that passes through the glass member 70 from the light source 80 and reaches the photocatalyst layer 71 can also be used as illumination means for illuminating the inside of the decompression storage chamber 24. However, if light is directly applied to the food (foodstuff) in the decompression storage chamber 24, there is a possibility that the nutritional component of the food is oxidized by the photo-oxidation reaction or the food is faded. Moreover, regarding vegetables, although it changes with the wavelengths, when a strong light is irradiated, a photosynthesis reaction is accelerated | stimulated and there exists a possibility of consuming the carbon dioxide in the pressure-reduction storage chamber 24. FIG.

  Therefore, as shown in FIG. 2, in this embodiment, a light shielding plate 41 that is opaque to the light from the light source 80 is provided between the food and the glass member 70. The light transmitted through the glass member 70 and the photocatalyst layer 71 is blocked by the light blocking plate 41 and is not directly irradiated to the food. In both the first method and the second method, the light shielding plate 41 can be provided in the decompression storage chamber 24. As shown by a dotted line in FIG. 2, gas (carbon dioxide, odor component gas, ethylene gas), moisture, and the like in the decompression storage chamber 24 circulate through a gap between the light shielding plate 41 and the ceiling portion 42. . In addition, the light-shielding plate 41 is not necessarily required as long as the position of the light source 80 is specified so that visible light is not directly applied to food, and oxidation of nutrient components can be appropriately suppressed.

  The structural example in the case of unitizing the glass member 70 and the light source 80 which have the photocatalyst layer 71 is demonstrated using FIGS. As shown in the perspective view of FIG. 3, a glass member 70 having a photocatalyst layer 71 and a light source unit 80 are detachably attached to the ceiling portion 42 of the decompression storage chamber body 40.

  FIG. 4 shows a state where the light source unit 80 is to be mounted after the glass member 70 is attached to the opening of the ceiling portion 42 via the seal member 72. FIG. 5 shows a state in the middle of attaching the light source unit 80 to the upper side of the glass member 70. FIG. 6 shows a state in which the light source unit 80 has been attached to the upper side of the glass member 70. FIG. 7 is an enlarged view of a part of FIG. Similarly, FIG. 8 is an enlarged view of a part of FIG. FIG. 9 is a top view of the ceiling portion 42 to which the light source unit 80 is attached.

  10 to 15 show how the light source unit 80 is assembled. First, FIG. 10 shows a state before the LED substrate 82 having the LEDs 83 is attached to the attachment space 85 formed on the lower surface of the LED cover 81. FIG. 11 shows a state in which the LED board 82 is inserted into the mounting space 85 in the LED cover 81. FIG. 12 shows a state in which the LED board 82 has been attached to the attachment space 85 in the LED cover 81.

  FIG. 13 is a perspective view of the state shown in FIG. FIG. 14 is a perspective view of the state shown in FIG. FIG. 15 is a perspective view of the state shown in FIG. 12 as viewed from the lower side of the LED cover 81.

  As shown in FIG. 15, a plurality of (for example, two) support portions 84 are formed on the lower surface side of the LED cover 81 so as to be positioned below the attachment space 85 and spaced apart in the width direction. The LED substrate 82 is supported by the support portions 84. Since the width dimension of the attachment space 85 is set according to the width dimension WL of the LED board 82, the LED board 82 is positioned in the width direction when the LED board 82 is attached to the attachment space 85. Further, as shown in FIG. 12 and the like, since the support portion 84 is provided to be inclined, the LED substrate 82 is positioned even in the longitudinal direction by inserting the LED substrate 82 to the back of the attachment space 85.

  Furthermore, since the LED substrate 82 is supported by the plurality of support portions 84 from the lower side, the LED substrate 82 does not naturally come off from the LED cover 81 and fall. The support portion 84 is provided at a position that does not interfere with the LED 83.

  A configuration in which the LED 83 is used as a positioning stopper is also possible. For example, when the width dimension WL of the LED board 82 is made smaller than the width dimension of the mounting space 85, the LED board 82 can be positioned in the width direction by contacting each LED 83 with the nearest support portion 84. . In this way, the LED 83 has not only a light emitting function but also a positioning stopper function, so that even when the LED board 82 is formed smaller than the mounting space 85, the LED board 82 can be formed without forming a dedicated stopper. Can be positioned.

  FIG. 16 shows the configuration of the seal member 72. 16A is a perspective view of the seal member 72, and FIG. 16B is a cross-sectional view of the seal member. On the outer peripheral surface of the seal member 72, a seal lip portion 72A and auxiliary lip portions 72B formed above and below the seal lip portion 72A are provided. The seal lip portion 72A is a member for sealing the inside of the decompression storage chamber 24 in a gas-liquid tight manner, and the auxiliary lip portion 72B is a member for preventing dust from entering the seal lip portion 72A.

  FIG. 17 shows a state in which the seal member 72 is placed on the ceiling portion 42 of the decompression storage chamber body 40. FIG. 18 shows a state in which the glass member 70 is placed on the upper surface side of the seal member 72. FIG. 19 shows a state where the light source unit 80 is further placed on the glass member 70. As shown in FIGS. 18 and 19, the photocatalyst layer 71 does not need to be formed on the entire lower surface side (inner surface) of the glass member 70, and may be formed only in a region exposed in the decompression storage chamber 24.

With reference to FIG. 20, the photocatalytic action in the decompression storage chamber 24 is demonstrated. When visible light including light having a predetermined wavelength (for example, around 470 nm) is output from the LED 83 of the light source 80, the visible light passes through the glass member 70 and enters the photocatalyst layer 71. When visible light enters the photocatalytic layer 71, electrons and holes are generated. Since holes are positively charged, they take electrons from moisture (H ₂ O) and generate OH radicals and hydrogen radicals. Further, electrons generated in the photocatalyst layer 71 transfer to oxygen molecules to generate oxygen radicals. Moisture that slightly evaporates from the food in the vacuum storage chamber 24 comes into contact with the photocatalyst layer 71 and becomes a raw material of radicals.

  Radicals decompose gas from food (for example, ethylene gas, methyl mercaptan, dimethyl disulfide) and minute organic substances (for example, various bacteria) floating in the vacuum storage chamber 24 into carbon dioxide and water. As an example, the decomposition reaction of ethylene gas generated from vegetables is shown in the following chemical formula (1).

C ₂ H ₄ + 4O ₂ → 2CO ₂ + 2H ₂ O (1)

  As can be seen from the chemical formula (1), ethylene gas generated from vegetables reacts with oxygen in the air to generate carbon dioxide and water. Vegetables in the vacuum storage chamber 24 are alive and breathe according to the concentration ratio of oxygen and carbon dioxide in the air. When the carbon dioxide concentration in the decompression storage chamber 24 becomes high, the pores of the vegetables are closed and the respiratory activity is suppressed, so that the deterioration of the vegetables is suppressed. Therefore, deterioration of taste and nutrition can be prevented over a relatively long period.

  Since the meat and fish stored in the vacuum storage chamber 24 have already died, they are different from the freshness retention mechanism of vegetables. However, odor component gas and organic gas generated from meat and fish are also decomposed into carbon dioxide and water by the photocatalytic reaction.

  Carbon dioxide generated by the photocatalytic reaction is easily dissolved in water. Accordingly, carbon dioxide, which is a product of the photocatalytic reaction, is dissolved in moisture on the food surface to become carbonic acid. Carbonic acid changes the pH value of the food surface. When the pH value of the food surface changes, it becomes inconsistent with the optimum pH of the microorganisms present on the food surface. Therefore, the propagation of microorganisms is suppressed.

  Moreover, since the enzyme reaction in food has an optimum pH, the enzyme reaction can be suppressed by changing the pH value of the food. The freshness of meat and fish decreases as the enzymatic reaction progresses. Therefore, the freshness of meat and fish can be maintained for a relatively long time by changing the pH value of the food to suppress the enzyme reaction.

  Furthermore, since the photocatalyst decomposes the odor component gas in the decompression storage chamber 24, the deodorization of the decompression storage chamber 24 can be performed. Furthermore, when moisture exists in the vacuum storage chamber 24, radicals are generated by the action of the photocatalyst. Therefore, the inside of the decompression storage chamber 24 can be sterilized by the action of radicals.

  Thus, when the carbon dioxide in the decompression storage room 24 increases, the freshness fall of meat and fish can be suppressed and the quality deterioration of vegetables can also be suppressed. However, carbon dioxide alone cannot suppress food oxidation. In the case of meat and fish, when an oxidation reaction occurs, fatty acids deteriorate and vitamins deteriorate.

  On the other hand, the storage chamber 24 of the present embodiment is not only a high carbon dioxide concentration but also a decompression storage chamber that is maintained at a state lower than atmospheric pressure. That is, the ratio of the oxygen concentration in the decompression storage chamber 24 is lower than that in the normal atmosphere, and conversely, the ratio of the carbon dioxide concentration in the decompression storage chamber 24 is higher than that in the ordinary atmosphere.

  Ordinary atmospheric components are 21% oxygen and 0.4% carbon dioxide. Nitrogen and other minor components are omitted. If the pressure in the decompression storage chamber 24 is lowered by 20% from the normal atmospheric pressure, oxygen is 16% and carbon dioxide is 0.032% compared to the composition at atmospheric pressure. Due to the photocatalytic reaction, carbon dioxide is generated in the reduced pressure storage chamber 24. For example, the carbon dioxide concentration in the reduced pressure storage chamber 24 increases to a value of about 0.13%. These specific numerical values are merely examples for understanding the operational effects of the present embodiment, and the present invention is not limited to these numerical values.

  As described above, in the reduced pressure storage chamber 24 of this embodiment, a decrease in oxygen concentration due to reduced pressure and an increase in carbon dioxide, which is a decomposition product due to a photocatalytic reaction, occur. The relative decrease in oxygen concentration due to the reduced pressure suppresses the oxidation reaction and can maintain the freshness of meat and fish for a relatively long time. Furthermore, as described above, the increase in carbon dioxide suppresses the enzymatic reaction of meat and fish, suppresses the growth of microorganisms, suppresses the respiration of vegetables, and prevents deterioration.

  Furthermore, since the decompression storage chamber 24 of this embodiment preserves food in a decompressed state, it extends the life of radicals compared to the case of normal atmospheric pressure, decomposes food gases such as ethylene gas, bacteria, and organic matter. It is thought that the efficiency of the decomposition reaction of can be improved. In a normal case, radicals and ions generated in the photocatalytic layer 71 react with molecules in the air and disappear immediately. However, in the reduced pressure state, the number of molecules in the reduced pressure storage chamber 24 is reduced, and the reaction rate becomes slow. Therefore, it is considered that the lifetime of radicals and ions is extended.

  An example of a method for controlling the decompression storage chamber 24 will be described with reference to FIG. The process shown in FIG. 21 is executed by the controller 90. The processing shown in FIG. 21 may be realized as a computer program or a hardware circuit.

  The controller 90 determines whether the door 50 is closed based on a signal from the door switch 92 that detects the open / closed state of the door 50 of the decompression storage chamber 24 (S10). When the door 50 of the decompression storage chamber 24 is closed (S10: YES), the controller 90 determines whether the door 6 is closed based on a signal from the door switch 91 that detects the open / closed state of the door 6 of the refrigerator compartment 2. Determine (S11). If the door switch 92 of the decompression storage chamber 24 is omitted, and the door switch 96 of the refrigerator compartment 2 is used to indirectly determine whether the door 50 of the decompression storage chamber 24 is opened or closed, S10 is omitted.

  When it is confirmed that the door 6 of the refrigerator compartment 2 is closed (S11: YES), the controller 90 outputs a control signal to the negative pressure pump 29 to drive it (S12), and the air in the decompression storage chamber 24 is changed. Let it drain. If neither the door 6 nor the door 50 is closed (S10: NO or S11: NO), the process returns to step S10.

  The controller 90 monitors the detection signal from the pressure sensor 28, and determines whether or not the pressure P1 in the decompression storage chamber 24 is equal to or lower than a predetermined pressure Pth set in advance (S13). The controller 90 operates the negative pressure pump 29 until the pressure P1 in the decompression storage chamber 24 becomes equal to or lower than the predetermined pressure Pth (S13: NO). When the pressure P1 in the decompression storage chamber 24 becomes equal to or lower than the predetermined pressure Pth (S13: YES), the controller 90 stops the negative pressure pump 29 (S14).

  After the depressurized storage chamber 24 is depressurized, the controller 90 determines that the concentration GC1 of the food gas in the depressurized storage chamber 24 is equal to or higher than a predetermined gas concentration GCTh based on the detection signal from the food gas sensor 93. Determine (S15).

  Here, the gas concentration threshold GCTh can be prepared for each type of food gas, such as a threshold for ethylene gas, a threshold for methyl mercaptan, a threshold for dimethyl disulfide, and the like. Then, when any one of the plurality of types of food gases reaches the threshold (S15: YES), the controller 90 turns on the light source 80 (S16). Thereby, as above-mentioned, a photocatalytic reaction is performed in a pressure-reduced environment, and food gas is decomposed | disassembled into a carbon dioxide and water. If all the concentrations of the target food gas are below the threshold (S15: NO), the controller 90 turns off the light source 80 (S17).

  In addition, it is good also as a structure which abbreviate | omits step S15 and makes the light source 80 light only for a fixed time instead. In this case, step S15 and step S17 are removed from the flowchart of FIG. 21, and the process immediately proceeds from step S14 to step S16. Then, the content of step S16 changes from “lights the photocatalyst light source” to “lights the photocatalyst light source for a predetermined time”. This improved step can be given S16A.

  Alternatively, since the light source 80 can be used as a lighting device for the decompression storage chamber 24, the light source 80 may be turned on while the door 6 of the refrigerator compartment 2 is open. Furthermore, the structure which switches the intensity | strength of the light irradiated from the light source 80, and / or the wavelength of light according to a condition may be sufficient. For example, when the light source 80 is used as an illuminating device for the decompression storage chamber 24, only some of the LEDs 83 are turned on, and when the light source 80 is used as a device for promoting the photocatalytic reaction, The LED 83 may be turned on. Or it is good also as a structure which mounts LED83 which can output the light of a different wavelength in the light source 80, and differs in the wavelength in the case of utilizing as an illuminating device, and the wavelength in promoting a photocatalytic reaction. Further, when the light source 80 is used as a lighting device, the number of lighting of the LED 83 is decreased and the wavelength is increased, and when the light source 80 is used as a photocatalytic reaction promoting device, the number of lighting of the LED 83 is increased and the wavelength is increased. A configuration in which the combination of the light intensity and the wavelength is changed depending on the situation of the refrigerator, such as shortening, may be used.

  The increase in carbon dioxide accompanying the photocatalytic action will be described with reference to FIGS. FIG. 22 shows the time change of the carbon dioxide concentration and the time change of the concentration of ethylene gas when avocado that generates a large amount of ethylene gas that promotes the deterioration of vegetables is accommodated in the sealed space.

  The characteristic line G10 shows the time change of the carbon dioxide concentration when the photocatalyst is used. The characteristic line G11 shows the time change of the carbon dioxide concentration when the photocatalyst is not used. The characteristic line G12 shows the time change of the ethylene concentration when the photocatalyst is used. A characteristic line G13 shows a time change when the photocatalyst is not used.

  The ethylene gas concentration gradually increases after the avocado is accommodated, but when the photocatalyst is not used, the ethylene gas concentration eventually maintains a substantially constant value (G13). When no photocatalyst is used, the concentration of carbon dioxide is almost constant (G11). On the other hand, when using a photocatalyst, ethylene gas is decomposed into carbon dioxide and water by the photocatalyst layer 71, so that the concentration of ethylene gas decreases as time passes (G12). Carbon dioxide, which is a decomposition product of ethylene gas, increases with time (G10).

  Therefore, it can be seen that ethylene gas generated from vegetables is decomposed by the photocatalyst to generate carbon dioxide. Since carbon dioxide hardly leaks outside in the sealed space, the carbon dioxide concentration in the sealed space increases. Since carbon dioxide suppresses the respiration of vegetables, it can suppress a decrease in freshness of vegetables. Vegetables are characterized by photosynthesis when exposed to light. Vegetables photosynthesize in response to red light near 630 nm. Since LED83 of a present Example mainly outputs the light of the wavelength of 470 nm vicinity, it can suppress the photosynthesis of vegetables.

  FIG. 23 shows the time change of the carbon dioxide concentration and the time change of the odor component gas concentration when meat or fish is stored in the sealed space.

  The characteristic line G14 shows the time change of the carbon dioxide concentration when the photocatalyst is not used. The characteristic line G15 shows the time change of the carbon dioxide concentration when the photocatalyst is used. A characteristic line G16 shows a change with time of the concentration of the odor component gas when the photocatalyst is not used. The characteristic line G17 shows the time change of the odor component gas when the photocatalyst is used.

  When the photocatalyst is not used, the odor component gas generated from meat or fish cannot be decomposed, so that the concentration of the odor gas component gradually increases (G16). When the photocatalyst is not used, carbon dioxide is not generated as a result of the photocatalytic reaction, and the concentration of carbon dioxide is almost constant (G14). On the other hand, when the photocatalyst is used, the odor component gas is decomposed into carbon dioxide and water by the photocatalyst, so that the concentration thereof decreases with time (G17). Since carbon dioxide is generated by the photocatalytic reaction, the concentration of carbon dioxide increases with time (G15).

  As shown in FIG. 23, when a photocatalyst is allowed to act while preserving meat and fish, the odor component gas is decomposed and carbon dioxide increases, and the carbon dioxide suppresses the enzyme reaction and the propagation of microorganisms. Is suppressed. Therefore, it can suppress that the freshness of meat and fish falls.

  The freshness retention effect by carbon dioxide when vegetables, meat, and fish are stored will be described with reference to FIGS. 24 to 26 are graphs in the case where the amount of remaining vitamin C when spinach, broccoli, and avocado are stored for 3 days in a sealed space is compared with and without photocatalyst. FIG. 24 shows a case where spinach and avocado are housed in a sealed space. FIG. 25 shows a case where broccoli and avocado are accommodated in a sealed space. Avocado was used to generate ethylene gas because it is a food that easily generates ethylene gas.

  FIG. 24 shows the result of comparing the amount of remaining vitamin C G22 in spinach when a photocatalyst is used and the amount of residual vitamin C G21 in spinach when no photocatalyst is used. It can be seen that the vitamin C residual amount G20 of spinach when the photocatalyst is applied is larger than the vitamin C residual amount G23 when the photocatalyst is not used.

  FIG. 25 shows the result of comparing the amount of residual vitamin C in broccoli G22 when using a photocatalyst and the amount of residual vitamin C in broccoli without using a photocatalyst. It can be seen that the residual vitamin C amount G22 when the photocatalyst is used is larger than the residual vitamin C amount when the photocatalyst is not used. From the above experimental results, it was confirmed that a decrease in freshness of vegetables can be suppressed by increasing carbon dioxide.

  A change in freshness of animal food (meat, fish) will be described with reference to FIGS. FIG. 26 shows a case where tuna is stored in an enclosed space for 3 days. The tuna K value G24 when the photocatalyst is used is lower than the K value G25 when the photocatalyst is not used. Thereby, it turns out that the freshness fall of a tuna is suppressed by the increase in a carbon dioxide.

  FIG. 27 shows the change in redness when beef is stored for 3 days in an enclosed space. It can be seen that the redness G26 when the photocatalyst is used is less changed than the redness G27 when the photocatalyst is not used and the discoloration of the meat is suppressed.

  In this embodiment configured as described above, the carbon dioxide concentration in the decompression storage chamber 24 in the sealed space can be increased. Therefore, the respiration of vegetables can be suppressed to prevent deterioration, the growth of microorganisms can be suppressed, and the enzymatic reaction of foods such as meat or fish can be reduced. Therefore, compared with the case where the carbon dioxide concentration is not increased, the effect of maintaining the freshness of the food is high.

  In the present embodiment, since the photocatalytic reaction is caused in the sealed decompression storage chamber 24, carbon dioxide, which is a product of the photocatalytic reaction, is confined in the decompression storage chamber 24, thereby effectively increasing the concentration of carbon dioxide. it can. Therefore, the above-described freshness maintaining action by carbon dioxide can be efficiently obtained.

  In the present embodiment, moisture that slightly evaporates from the food stored in the reduced pressure storage chamber 24 is used as a raw material for radicals, and the odor component gas and bacteria are decomposed into carbon dioxide and water by the radicals. The decomposition products, carbon dioxide and water, are trapped in a sealed storage chamber. Moisture is reused as a raw material for radicals, and the humidity in the decompression storage chamber 24 is kept high. Carbon dioxide realizes the above-described freshness maintaining action.

  In the present embodiment, the food is stored in the sealed decompression storage chamber 24 to perform the photocatalytic reaction, so that the odor component gas and moisture are used as radical raw materials, and further, the carbon dioxide which is a decomposition product by the photocatalytic reaction. Is used to maintain the freshness of food. Thus, in a substantially closed environment, the photocatalytic action of decomposition and sterilization of the odor component gas by the photocatalytic reaction and the action of carbon dioxide can be combined to suppress a decrease in freshness of food.

  Furthermore, in the present embodiment, the carbon dioxide concentration in the vacuum storage chamber 24 can be increased efficiently because the sealed vacuum storage chamber 24 is set to a state lower than the atmospheric pressure to increase carbon dioxide. Moreover, since the inside of the storage chamber 24 is depressurized, it is possible to suppress leakage of carbon dioxide to the outside of the storage chamber 24. This is because the pressure outside the storage chamber 24 is higher. Furthermore, since the number of air molecules in the storage chamber 24 can be reduced, the lifetime of radicals can be increased, and the possibility that radicals decompose odor component gases, germs, and the like can be increased.

  A second embodiment will be described with reference to FIG. Each of the following embodiments, including the present embodiment, corresponds to a modification of the first embodiment, and therefore the description will focus on differences from the first embodiment. In this embodiment, a mechanism for carrying out the photocatalyst is arranged on the bottom surface side of the decompression storage chamber 24.

  In the vacuum storage chamber 24 shown in FIG. 28, a glass member 70 having a photocatalyst layer 71 is provided via a seal member 72 at the center of the bottom 43 of the vacuum storage chamber main body 40. A food tray 60 is provided above the photocatalyst layer 71 through a gap. The odor component gas derived from the food in the food tray 60 enters through the gap between the food tray 60 and the photocatalyst layer 71 and is decomposed by the photocatalyst layer 71. Carbon dioxide and moisture, which are decomposition products of the photocatalytic reaction, enter the food tray 60 through the gaps, thereby suppressing the enzymatic reaction and respiratory action of food or suppressing the growth of microorganisms.

  When the food tray 60 is formed from a transparent material, light from the light source 80 may be irradiated to the food in the food tray 60, and the food may be deteriorated by a photooxidation reaction or the like. In this case, a metal plate 41 formed of aluminum or stainless steel may be installed at the bottom of the food tray 60. This metal plate 41 not only has the function as the light shielding plate described in the first embodiment, but also exhibits the effect of taking away the heat of the food and cooling it.

  Configuring this embodiment like this also achieves the same effects as the first embodiment. Further, in this embodiment, the photocatalyst layer 71 and the light source 80 are provided at the bottom 43 of the decompression storage chamber 24, and therefore the heat radiating plate 41 for accelerating the cooling prevents the light from the light source 80 from being irradiated on the food. It can also be used as a light shielding plate. Since one metal plate 41 can have a plurality of functions, the performance of the decompression storage chamber 24 can be enhanced while suppressing an increase in manufacturing cost.

  A third embodiment will be described with reference to FIG. FIG. 29 is a cross-sectional view of the refrigerator according to the present embodiment, and a glass member 70 having a photocatalyst layer 71 and a light source 80 are arranged, for example, on the ceiling of the vegetable compartment 5. In general, the vegetable room 5 is less airtight than the vacuum storage room 24, but if the predetermined airtightness can be obtained, the carbon dioxide concentration can be increased by photocatalytic reaction to suppress vegetable respiration. Let's go. It is good also as a structure which forms the whole vegetable chamber 5 or its part airtight, and raise | generates a photocatalytic reaction in the airtight space.

  A fourth embodiment will be described with reference to FIGS. 30 and 31. FIG. In this embodiment, a device for generating a photocatalytic reaction is configured separately from a sealed space such as the decompression storage chamber 24.

  As shown in FIG. 30 (a), a photocatalytic reaction generator 200 for generating a photocatalytic reaction includes, for example, a photocatalytic unit 210 having a photocatalytic layer 212 formed on the inner surface, and a light source disposed inside the photocatalytic unit 210. The power supply unit 230 for supplying power to the light source unit 220 may be provided.

  FIG. 30B is a cross-sectional view of the photocatalyst unit 210. The photocatalyst unit 210 includes, for example, a support member 211 formed of an opaque resin material or metal material in a cylindrical shape, a triangular tube shape, a square tube shape, a pentagonal tube shape, a hexagonal tube shape, and the like, and an inner surface of the support member 211. And a photocatalyst layer 212 formed on the whole or in a predetermined region. The reason why the support member 211 is opaque is to reduce the possibility that the light generated in the support member 211 is directly irradiated to the food. Therefore, a mesh member or the like for suppressing light leakage may be provided at the openings on both ends of the support member 211.

  The light source unit 220 includes an LED substrate 221 disposed inside the support member 211 and at least one LED 222 provided on the LED substrate 221. In this embodiment, a plurality of LEDs 222 are arranged at a predetermined interval along the longitudinal center line of the elongated plate-like LED substrate 221.

  LED222 is arrange | positioned so that the both directions of the upper surface and lower surface of LED board | substrate 221 can be illuminated. As a first method, for example, the LED 222 may be embedded in the center of the LED substrate 221 in the thickness direction, and light may be emitted from one LED 222 toward the upper and lower surfaces. As a second method, the LED 222 may be separately provided on the upper surface and the lower surface of the LED substrate 221. The first configuration is lower in manufacturing cost than the second method.

  The power supply unit 230 is composed of, for example, a dry battery, a battery, a power line for home use, and the like, and is connected to the light source unit 220 via an electric wire 231. By turning on the switch 232, power is supplied from the power supply unit 230 to the LED 222 of the light source unit 220. Note that a timer may be provided and the switch 232 may be turned off when a predetermined time elapses after the switch 232 is turned on.

  FIG. 31 is a schematic diagram showing an example of use of the photocatalytic reaction generator 200. For example, the food and the photocatalytic reaction generator 200 are accommodated in an openable / closable sealed container 300 such as a cooler box, and the lid 301 is closed. As a result, the concentration of carbon dioxide in the sealed container 300 increases, and the same effect as in the first embodiment is achieved.

  Further, in the present embodiment, since the sealed container 300 and the photocatalytic reaction generator 200 are formed separately, the photocatalytic reaction generator 200 is accommodated in a container having a certain degree of hermeticity such as a cooler box or a lunch box. It is possible to suppress a decrease in freshness of food. In addition, the photocatalytic reaction generator 200 used in a certain sealed container 300 can be used in another sealed container 300, which is easy to use. The sealed container 300 does not have to be completely airtight. What is necessary is just to have airtightness to such an extent that gas (food gas, carbon dioxide, etc.) does not circulate freely inside and outside the container. The higher the airtightness of the container, the higher the concentration of carbon dioxide can be efficiently increased, and the decrease in freshness of food can be suppressed.

  In addition, the structure of the photocatalyst part 210 is not restricted to a cylindrical shape. Any structure may be used as long as gas from food can reach the photocatalyst layer 212 and carbon dioxide generated in the photocatalyst layer 212 can flow toward the food. For example, a honeycomb shape or a sphere shape having an opening may be used.

  A fifth embodiment will be described with reference to FIG. The photocatalytic reaction generator 200 of the present embodiment configures the power supply unit 230 as a solar power generator. The power supply unit 230 configured as a solar power generation device is provided on the outer surface of the lid 301 of the sealed container 300, for example. The power supply unit 230 and the light source unit 210 are connected via an electric wire 231 provided through the lid 301. The electric wire 231 is attached to the lid 301 via a seal member (not shown) such as an O-ring. The power supply unit 230 may be provided with a switch 232 or a timer. In addition, the power supply unit 230 may include a dry battery, a battery, or the like as an auxiliary power supply.

  The airtight container 300 may be provided with a manual suction pump 310. The suction pump 310 is attached to the main body of the hermetic container 300 or the lid 301 via a seal member (not shown) such as an O-ring. The user closes the lid 301 after storing the food in the sealed container 300 and manually operates the suction pump 310. Thereby, the air in the airtight container 300 is sucked and discharged into the atmosphere. The light source unit 210 may be turned on before the inside of the sealed container 300 is depressurized by the suction pump 310, or may be turned on after the pressure is reduced. Note that the suction pump 310 may be configured as a battery-type suction pump that is operated by power supply from the power supply unit 230.

  Configuring this embodiment like this also achieves the same effects as the fourth embodiment. Furthermore, in this embodiment, since the power supply unit 230 is configured as a solar power generation device, it is possible to suppress a decrease in the freshness of food even in places such as mountains, seas, and deserts, which is easy to use. Also in the example shown in the fourth embodiment, a manual or electric suction pump may be provided. When an electric pump is provided, the power supply unit 230 and the suction pump 310 are electrically connected by the electric wire 232. The electric wire 232 may be provided in the sealed container 300, may be provided on the surface of the sealed container 300, or may be provided inside the wall portion of the sealed container 300.

  The present invention is not limited to the above-described embodiment. A person skilled in the art can make various additions and changes within the scope of the present invention.

  For example, the configuration shown in the fourth embodiment or the fifth embodiment can be expressed as follows. Reference numerals attached to the constituent elements are examples for understanding, and are not intended to limit the configuration of the following invention to the illustrated configuration.

Expression 1.
A photocatalytic reaction generator (200) for generating a photocatalytic reaction in a container containing food,
A photocatalytic portion (210) having a photocatalytic layer (212);
A light source unit (220) for irradiating the photocatalyst layer with light;
A power supply unit (230) for supplying power to the light source unit;
A photocatalytic reaction generator.
Expression 2.
The photocatalytic reaction generator according to expression 1, wherein the photocatalyst unit, the light source unit, and the power supply unit are configured so as to be integrated into and removed from the container.
Expression 3.
The said photocatalyst part and the said light source part are provided in the inside of the said container, The said power supply part is comprised as a solar power generation device which generate | occur | produces with sunlight, and is provided in the exterior of the said container. Photocatalytic reaction generator.
Expression 4.
4. The photocatalytic reaction generator according to any one of Expressions 1 to 3, wherein the container is provided with a suction device (310) for sucking out and discharging air inside the container.

  1: refrigerator main body, 2: cold storage room, 3, 4: freezing room, 5: vegetable room, 6-9: door, 24: decompression storage room, 28: pressure sensor, 29: pump, 40: decompression storage room body, 41: Shading plate, 42: Ceiling part of decompression storage room, 43: Bottom part of decompression storage room, 60: Food tray, 70: Glass member, 71: Photocatalyst layer, 72: Seal member, 80: Light source, 81: LED cover , 82: LED substrate, 83: LED, 90: controller, 91: door switch for refrigerator compartment, 92: door switch for decompression storage chamber, 93: food gas sensor, 200: photocatalytic reaction generator, 210: photocatalyst section, 211: Support part, 212: Photocatalyst layer, 220: Light source part, 221: LED substrate, 222: LED, 230: Power supply part, 231, 232: Electric wire, 232: Switch, 300: Container, 301: Lid, 310: Suction Pump

Claims (1)

In a refrigerator comprising a storage room for storing food,
The storage chamber has a sealed structure,
A carbon dioxide increasing device for increasing carbon dioxide in the storage chamber is provided.
refrigerator.

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