JP2004333043A - Ultradeep freezer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To satisfy two kinds of temperature specifications of very low temperature and low temperature by one ultradeep freezer, to reduce an installation space of the freezer, and to reduce the cost. <P>SOLUTION: This ultradeep freezer where a heat insulating casing 1 and a heat insulating door 3 made out of a heat insulating material, and articles accommodated inside of the heat insulating casing 1 are cooled by a dual freezer where the low-temperature side and high-temperature side cycles are cascade-connected, comprises a plurality of storages 5a, 5b formed by partitioning the heat insulating casing 1 by a heat insulating wall 2, and independently mounting the heat insulating doors 3, and cooling units 7a, 7b respectively mounted in the storages. One of the cooling unit is connected with the low-temperature side cycle, and the other is connected with the high-temperature side cycle. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ultra-low temperature freezer that maintains the inside of an insulated housing at an ultra-low temperature and stores stored items.
[0002]
[Prior art]
The ultra-low-temperature freezer is used for long-term storage of samples such as cells and blood, and uses a binary refrigeration system as a refrigerating device to cool and maintain the inside of the storage at an ultra-low temperature of -85 ° C or lower. It is known to cascade a circuit and a low-temperature side refrigerant circuit, and is described in, for example, Patent Document 1.
[0003]
[Patent Document 1]
JP 10-300330 A
[Problems to be solved by the invention]
In places where ultra-low temperature freezers are used, for example, bio-related laboratories, cells and blood specimens are stored under ultra-low temperature conditions of -85 ° C or lower for long-term storage. The temperature is a low temperature condition of −20 ° C. to −30 ° C., and there are two types of cooling temperatures required for the freezer.
However, in the above-mentioned conventional technology, since there is only one storage room and the temperature specification is only the ultra-low temperature condition, it is necessary to install a freezer having a different temperature specification separately from the ultra-low temperature freezer, and the installation space of the freezer is large. Cost is also high.
[0005]
SUMMARY OF THE INVENTION It is an object of the present invention to satisfy two kinds of temperature specifications of ultra-low temperature and low temperature with one ultra-low temperature freezer, and to reduce the installation space and cost of the freezer.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a binary refrigeration apparatus in which a heat-insulating housing and a heat-insulating door formed of a heat-insulating material, and a low-temperature side and a high-temperature side cycle are cascaded with articles housed inside the heat-insulating housing. In the ultra-low-temperature freezer that cools down, the heat-insulating housing is divided by heat-insulating walls, and includes a plurality of storages provided with independent heat-insulating doors, and coolers attached to the respective storages, and one of the coolers is provided. The low-temperature side cycle is connected to the high-temperature side cycle.
[0007]
In the above, the low-temperature cycle and the high-temperature cycle constitute a binary refrigeration cycle (two-stage cascade refrigeration cycle) connected via a cascade condenser, and the cooler connected to the high-temperature cycle is a cascade condenser. Is desirably connected in parallel.
[0008]
Further, in the above, the low-temperature cycle and the high-temperature cycle constitute a binary refrigeration cycle (two-stage cascade refrigeration cycle) connected via a cascade condenser, and the cooler connected to the high-temperature cycle is a cascade condenser. It is desirable to provide an electromagnetic valve upstream of the cooler and the cascade condenser, respectively, and to switch the flow of the refrigerant to the cooler and the cascade condenser by opening and closing the electromagnetic valves.
[0009]
Furthermore, in the above, it is desirable that the capacity of the compressor used in the high-temperature side cycle can be controlled by an inverter.
Further, in the above-mentioned one, the storage is made into three chambers, the coolers of two chambers are connected in parallel to the low-temperature side cycle, solenoid valves are provided on the upstream side, and the flow of the refrigerant is controlled by opening and closing the solenoid valves. It is desirable to switch.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a side sectional view of an ultra-low temperature freezer according to an embodiment. Reference numeral 1 denotes a heat-insulating housing, the inside of which is separated by a heat-insulating wall 2, and a heat-insulating door 3 is provided for each. Thereby, the heat transfer from the surroundings is blocked by the heat insulating material 4, and the storages 5a and 5b are respectively independent spaces.
Each of the storages 5a and 5b is provided with a temperature sensor 6 for detecting an internal temperature, and the coolers 7a and 7b are provided with a cooling pipe 7 attached in close contact with the outside of the inner tank material 1a. It is a tube-on-sheet type having the material 1a as a heat transfer surface. The cooler 7a attached to the storage 5a is connected to the low-temperature cycle of the binary refrigeration system, and the cooler 7b attached to the storage 5b is connected to the high-temperature cycle.
[0011]
The storage 5a is a storage under the specification of the ultra low temperature condition, and the storage 5b is a storage under the specification of the low temperature condition. As a form of the cooler, a tube-on-sheet type is generally used in an ultra-low-temperature freezer, but a fin tube type cooler may be used. In addition, the positional relationship of the cooler (storage) connected to the low-temperature cycle and the high-temperature cycle of the binary refrigeration system is such that the upper storage 5a has a low-temperature condition and the lower storage 5b has an ultra-low temperature specification, A storage room at an ultra-low temperature condition and a storage room at a low temperature condition may be arranged side by side.
[0012]
FIG. 2 is a schematic diagram of a refrigeration cycle system of a binary refrigeration apparatus, in which a low-temperature side cycle and a high-temperature side cycle are connected via a cascade condenser to form a binary refrigeration cycle (two-stage cascade refrigeration cycle). The main parts of the binary high-temperature side cycle are a compressor 8, a condenser 9, a cascade condenser 10, a cooler 7b and a cascade condenser, solenoid valves 11a and 11b provided upstream of each cooler, and capillary tubes 12a and 12b. The binary low-temperature side cycle includes a compressor 13, a cascade condenser 10, a capillary tube 14, and a cooler 7a.
The cooler 7b of the high-temperature side cycle is connected in parallel with the cascade condenser 10, and controls the flow of the refrigerant by opening and closing the solenoid valves 11a and 11b provided on the respective upstream sides, only the cascade condenser 10 side, only the cooler 7b side, Switching can be performed on both the cascade condenser 10 side and the cooler 7b side.
[0013]
The opening and closing of the solenoid valves 11a and 11b is controlled by comparing the measured value of the temperature sensor 6 provided in each storage with the set temperature of each storage. When both the storages 5a and 5b need to be cooled, The solenoid valves 11a and 11b are both opened, and the refrigerant in the high-temperature cycle flows to both the cascade condenser 10 and the cooler 7b, and the refrigerant in the low-temperature cycle is cooled and liquefied on the cascade condenser 10 side, and is cooled in the cooler 7b. The inside of the storage 5b is cooled. When the storage 5a needs to be cooled and 5b does not need to be cooled, the solenoid valve 11a is opened and 11b is closed, and the refrigerant flows only to the cascade condenser 10 side. When cooling is required, the solenoid valve 11a is closed and 11b is opened, so that the refrigerant flows only to the cooler 7b side. The low-temperature side cycle is ON-OFF controlled depending on whether or not the storage 5a needs to be cooled, and is turned OFF when cooling is unnecessary. In other words, by switching the flow of refrigerant in the high-temperature side cycle according to the condition of each storage in an ultra-low temperature freezer equipped with one binary refrigeration system, two types of temperature specifications, low-temperature condition and ultra-low temperature condition, are available. The temperature of the storage can be controlled.
[0014]
In addition, by mounting the inverter 15 and controlling the capacity of the compressor 8 in the high-temperature cycle according to the condition of each storage, the operation of the binary refrigeration system can be stabilized and the power consumption required for operation can be reduced. It becomes. For example, when both the storages 5a and 5b require cooling, 100% operation is performed because the required cooling capacity of the high-temperature cycle is large, and when only the storage 5a is required to be cooled, 75% operation is performed. When only cooling is required, the capacity is controlled in accordance with the required cooling capacity, such as 50% operation, so that the capacity balance between the high temperature side and the low temperature side of the binary refrigeration cycle (two-stage cascade refrigeration cycle) is in an appropriate state. And stable operation becomes possible.
[0015]
FIG. 3 shows a case where the number of storages is three, and is a schematic diagram of a cycle system in the case of two ultra-low temperature conditions and one low temperature condition. Two coolers 7a connected to the low-temperature side cycle are connected in parallel, and an electromagnetic valve 16 and a capillary tube 14 are provided on each upstream side. As in the case of the two chambers, the flow of the refrigerant to the cooler is controlled by opening and closing each solenoid valve according to the temperature in each storage, and the temperature in the storage is controlled. In addition, even in the case of a multi-chamber, each is divided into a high-temperature side cycle and a low-temperature side cycle according to the temperature specification, and connected in parallel. Temperature control becomes possible. By making the small-capacity storage multi-unit as described above, it is possible to subdivide the effect of the internal temperature rise due to the opening and closing of the door. Further, by controlling the capacity according to the temperature in each storage provided with a cooler having an inverter 17 and a compressor connected to the low-temperature cycle of the low-temperature cycle compressor 13, the compressor 8 of the high-temperature cycle described above is controlled. Together with the capacity control, it is possible to stabilize the operation of the binary refrigeration cycle (two-stage cascade refrigeration cycle) and reduce the power consumption.
[0016]
As described above, by switching the flow of the refrigerant in the high-temperature side cycle according to the situation of each of the plurality of storages in the ultra-low temperature freezer equipped with one binary refrigeration system, the low-temperature condition and the ultra-low temperature condition are obtained. The temperature control of the storage of two kinds of temperature specifications becomes possible. In addition, since it is integrated as one binary refrigeration apparatus, it is possible to reduce the installation space of the freezer, reduce the number of parts of the ultra-low temperature freezer, and reduce the manufacturing cost.
[0017]
【The invention's effect】
As described above, according to the present invention, a single ultra-low temperature freezer can satisfy two types of temperature specifications, ultra-low temperature and low temperature, and can reduce the installation space and cost of the freezer.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing a storage room portion of an ultra-low temperature freezer according to an embodiment of the present invention.
FIG. 2 is a refrigeration cycle system diagram of an ultra-low temperature freezer in one embodiment.
FIG. 3 is a refrigeration cycle system diagram in another embodiment in which three storage rooms for the ultra-low temperature freezer are provided.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Insulated housing, 2 ... Insulated wall, 3 ... Insulated door, 5a ... Storage (ultra low temperature specification), 5b ... Storage (low temperature specification), 7 ... Cooling pipe, 7a, 7b ... Cooler, 8 ... Compressor (High temperature side) 10: Cascade condenser, 11a, 11b, 16: Solenoid valve, 12a, 12b, 14: Capillary tube, 13: Compressor (low temperature side), 15, 17: Inverter.

Claims (5)

An insulated housing and an insulated door formed of an insulating material, and an ultra-low-temperature freezer that cools an article stored in the insulated housing with a binary refrigeration apparatus in which a low-temperature side and a high-temperature side cycle are cascaded.
The heat-insulating housing is separated by a heat-insulating wall, comprising a plurality of storages provided with independent heat-insulating doors, and a cooler attached to each of the storages,
An ultra low temperature freezer, wherein one of the coolers is connected to the low temperature side cycle and the other is connected to the high temperature side cycle. 2. The device according to claim 1, wherein the low-temperature cycle and the high-temperature cycle constitute a binary refrigeration cycle connected via a cascade condenser, and the cooler connected to the high-temperature cycle comprises the cascade condenser. An ultra-low-temperature freezer, which is connected in parallel with the above. 2. The device according to claim 1, wherein the low-temperature cycle and the high-temperature cycle constitute a binary refrigeration cycle connected via a cascade condenser, and the cooler connected to the high-temperature cycle comprises the cascade condenser. An ultra-low-temperature freezer, which is connected in parallel with the cooling device and an electromagnetic valve is provided on the upstream side of the chiller and the cascade condenser, and the flow of the refrigerant to the chiller and the cascade condenser is switched by opening and closing the electromagnetic valve. . 2. The ultra low temperature freezer according to claim 1, wherein a capacity of the compressor used in the high temperature side cycle can be controlled by an inverter. 2. The apparatus according to claim 1, wherein the storage has three chambers, two coolers are connected in parallel to the low-temperature side cycle, and solenoid valves are provided upstream of each of the coolers, and the solenoid valves are opened and closed. An ultra-low temperature freezer characterized by switching the flow of refrigerant by means of

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