JP2012162669A - Refrigerant for refrigerating machine, and household ultracold freezing storehouse - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerant for a refrigerating machine of a household ultracold freezing storehouse meeting characteristics including the global warming potential, the silence property, and the energy saving property, which are required as a refrigerant.SOLUTION: The refrigerant for a refrigerating machine is formed as a three-component mixed refrigerant containing carbon dioxide, isobutane and propane in a mixing ratio of 3:4:4. The refrigerating machine to cool a freezing storage chamber for ultracold freezing is combined with a freezing storehouse body having the freezing storage chamber.

Description

  TECHNICAL FIELD The present invention relates to a refrigerant suitable for a refrigerator for a household ultra-low temperature freezer and a household ultra-low temperature freezer using the refrigerant.

  There is frozen storage as a method for long-term storage of foods, and ultra-low temperature freezing is a freezing method that further enhances storage stability by freezing. In ultra-low temperature freezing, frozen storage is performed at an ultra-low temperature of about -60 ° C. Therefore, ultra-low temperature freezing can effectively avoid the destruction of cells of fresh foods such as meat and seafood, which are the main cryopreservation targets, in the freezing process, and keep fresh foods high in freshness for a longer period of time. It is possible to save while.

  Making such ultra-low temperature freezing easy to use in ordinary homes is particularly effective in further enhancing the abundance of eating habits due to the recent distribution structure of fresh foods. In other words, with the recent development of online shopping, fresh foods sent directly from the production areas are easily available to individual households, and the eating habits are becoming richer. By making it easy to use ultra-low temperature freezing in homes, there is no need to worry about long-term preservation of fresh foods, and it is easier to purchase fresh foods through distribution structures such as online shopping. It becomes possible to further enhance the richness of eating habits.

  By the way, there is an important problem that needs to be taken into consideration in order to make ultra-low temperature refrigeration easy to use in ordinary households, that is, to widely disseminate freezers for ultra-low temperature freezing in ordinary households. Specifically, it is a problem of refrigerants used in refrigerators for household ultra-low temperature freezers.

  In anticipation of widespread use of ordinary cryogenic freezers in ordinary households, the refrigerant used in the refrigerator is accompanied by greenhouse gas problems when it is released to the environment for some reason. For this reason, it is desired that the refrigerant used in the domestic ultra-low temperature freezer (the refrigerant used in the refrigerator of the domestic ultra-low temperature freezer) has a global warming potential as small as possible. However, in the conventional ultra-low temperature freezer, specific chlorofluorocarbons (CFC, HCFC) and fluorocarbons are used as refrigerants (for example, Patent Document 1), and those suitable for ultra-low temperature freezing have a global warming potential. It is several thousand orders, and it must be said that it is inappropriate for the global warming potential as a refrigerant for household cryogenic freezers in anticipation of widespread use in ordinary households.

  Therefore, it is conceivable that carbon dioxide having a low global warming potential of 1 can be used as a refrigerant, enabling ultra-low temperature freezing. However, because household ultra-low temperature freezers are used daily in ordinary households, high silence and high energy-saving performance are required, but carbon dioxide refrigerant is suitable for this quietness and energy-saving performance. Lack. That is, as disclosed in, for example, Patent Document 2, the carbon dioxide refrigerant requires a large amount of compressive power, which increases power consumption during operation and makes it difficult to avoid an increase in noise. It must be said that it lacks suitability for high silence and energy saving required.

  As the refrigerant for ultra-low temperature freezing, ammonia can be used as disclosed in Patent Document 3, for example. However, the ammonia refrigerant has an ammonia odor problem when it leaks, and it must be said that the refrigerant is not suitable as a refrigerant for a home cryogenic freezer.

Japanese Patent Laid-Open No. 2004-333909 JP 2010-276238 A JP 2006-214611 A

  As described above, widespread use of household ultra-low temperature freezers is effective in increasing the abundance of eating habits, but there remains a problem regarding refrigerants used in household ultra-low temperature freezers. The present invention has been made in the background of such circumstances, and has characteristics required as a refrigerant for a refrigerator in a domestic ultra-low temperature freezer for any of the global warming potential, silence, energy saving, and odor problems. Providing a satisfactory refrigerant for a refrigerator is a first problem, and providing a home ultra-low temperature freezer using such a refrigerant in a refrigerator is a second problem.

  Regarding solving the first problem, first, the global warming potential was emphasized, and attention was paid to carbon dioxide having a small global warming potential. However, as described above, if the refrigerant is composed of carbon dioxide alone, a large amount of compression power is required, and power consumption and noise during operation increase, so that silence and energy saving cannot be achieved. Therefore, earnest examination and experiment were repeated for the composition composition of the mixed solvent that can achieve quietness and energy saving while avoiding the odor problem while taking advantage of the small global warming potential of carbon dioxide. As a result, by using a three-component mixed refrigerant that mixes carbon dioxide with isobutane and propane, all of the global warming potential, silence, energy saving, and odor problems can be used as refrigerants in refrigerators for household cryogenic freezers. It is possible to satisfy the required characteristics, and in particular, when the mixing ratio of carbon dioxide, isobutane, and propane is set to 3: 4: 4 by weight, it is required as a refrigerant for a refrigerator in a home cryogenic freezer. We have found that it is excellent in satisfying properties.

  Accordingly, the refrigerant for a refrigerator according to the present invention for solving the first problem is characterized by containing carbon dioxide, isobutane and propane.

  In the present invention, the refrigerant for a refrigerator as described above is characterized in that the mixing ratio of carbon dioxide, isobutane and propane is 3: 4: 4 by weight.

  Further, in the present invention, in order to solve the second problem, a freezing machine for home use in which a freezer body having a freezing storage room is combined with a freezer for cooling the freezing storage room for ultra-low temperature freezing, the freezer The above-described refrigerant for a refrigerator is used as the refrigerant.

  According to the present invention as described above, a refrigerant for a refrigerator that satisfies the characteristics required as a refrigerant for a refrigerator in a domestic ultra-low temperature freezer can be obtained for any of global warming potential, quietness, energy saving, and odor problems. In addition, by using such a refrigerant, it is possible to realize a household ultra-low temperature freezer having excellent characteristics with respect to global warming potential, noise reduction, energy saving, and odor problems.

It is a figure which shows the external appearance structure of the household ultra-low temperature freezer by one Example. It is a figure which shows the circuit structure of the refrigerator in a household ultra-low temperature freezer.

  FIG. 1 shows a simplified external configuration of a domestic ultra-low temperature freezer according to an embodiment, and FIG. 2 shows a simplified circuit configuration of a refrigerator incorporated in the domestic ultra-low temperature freezer of FIG. The household ultra-low temperature freezer 1 of this embodiment includes a freezer body 2. The freezer main body 2 is a chest type, and a frozen storage chamber 3 surrounded by a heat insulating layer of, for example, about 100 mm is formed inside to store the frozen storage product. The inlet / outlet port 4 is formed in a rectangular box shape having an open top formed at the top. The freezer body 2 is provided with a rotating upper lid 5 for closing the entrance 4. The rotating upper lid 5 is attached to the side edge of the freezer main body 2 via a hinge portion 6 so that it can be opened and closed by a rotating operation with the hinge portion 6 as a fulcrum.

  The freezer body 2 incorporates the refrigerator 11 shown in FIG. Specifically, a refrigerator storage unit (not shown in FIG. 1) is formed inside the freezer main body 2 so as to be closed by the storage unit cover 12, and the refrigerator is stored in the refrigerator storage unit. 11 is incorporated (however, an evaporator 21 in the refrigerator 11 described later is incorporated in a wall surface surrounding the frozen storage chamber 3).

  Further, the freezer main body 2 is assembled with a temperature controller 13. The temperature controller 13 includes an adjustment unit 14 and a display unit 15. The adjusting unit 14 is provided with a temperature setting button 16 so that the temperature of the frozen storage chamber 3 can be set by operating the temperature setting button 16. The display unit 15 digitally displays the set temperature set by the adjusting unit 14 and the measured temperature of the frozen storage chamber 3.

  The refrigerator 11 includes a compressor 17, a condenser 18, a filter dryer 19, a capillary tube 20, an evaporator 21, and an accumulator 22. In this refrigerator 11, the refrigerant (refrigerant refrigerant) is compressed by the compressor 17, and then supplied to the evaporator 21 through the condenser 18, the filter dryer 19, and the capillary tube 20 in this order, and is evaporated by the evaporator 21. By doing so, the freezing capacity is exhibited and the freezing storage chamber 3 is cooled for ultra-low temperature freezing. The refrigerant having passed through the evaporator 21 returns to the compressor 17 through the accumulator 22 and repeats the above circulation.

A three-component mixed refrigerant is used as the refrigerant in the refrigerator 11 as described above. Specifically, a three-component mixed refrigerant obtained by mixing liquid carbon dioxide (CO ₂ ), isobutane (2-methylpropane; C ₄ H ₁₀ ), and propane (C ₃ H ₈ ) is used. The mixing ratio of carbon dioxide, isobutane, and propane in such a three-component mixed refrigerant is particularly preferably 3: 4: 4 by weight.

  The three-component refrigerant mixture of carbon dioxide, isobutane and propane achieves quietness and energy saving while taking advantage of the low coefficient of global warming coefficient due to carbon dioxide, and can also avoid odor problems. For all of the quietness, energy saving, and odor problems, the characteristics required as refrigerants for refrigerators in household ultra-low temperature freezers are satisfied. Therefore, by using such a three-component mixed refrigerant in the refrigerator 11, excellent characteristics can be given to the household ultra-low temperature freezer 1.

  Here, by mixing isobutane and propane with carbon dioxide, the above-described refrigerant characteristics can be realized by the boiling points of isobutane and propane being −12 ° C. and −42.09 ° C. It is thought that the boiling point of -78.5 ° C is sufficiently higher, the global warming potential of isobutane and propane is limited to tens of orders, and that the molar masses of isobutane and propane are appropriate. It is done.

  As mentioned above, although the form for implementing this invention was demonstrated, this is only a representative example and this invention can be implemented with various forms in the range which does not deviate from the meaning.

DESCRIPTION OF SYMBOLS 1 Home cryogenic freezer 2 Freezer main body 3 Freezer storage room 11 Refrigerator

Claims (3)

  A refrigerant for a refrigerator comprising carbon dioxide, isobutane and propane.   The refrigerant for a refrigerator according to claim 1, wherein a mixing ratio of the carbon dioxide, isobutane, and propane is 3: 4: 4 by weight.   It is a domestic ultra-low temperature freezer comprising a freezer body having a freezer storage chamber and a refrigerator that cools the freezer storage chamber for ultra-low temperature freezing, and the freezer according to claim 1 or 2 as a refrigerant of the freezer. A cryogenic freezer for home use, characterized in that a refrigerant for the machine is used.

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