WO2019163662A1

WO2019163662A1 - Refrigeration device

Info

Publication number: WO2019163662A1
Application number: PCT/JP2019/005522
Authority: WO
Inventors: 峻豊岡; 小林　晋
Original assignee: Ｐｈｃホールディングス株式会社
Priority date: 2018-02-20
Filing date: 2019-02-15
Publication date: 2019-08-29

Abstract

This refrigeration device is provided with a compressor, a condenser, a throttle device and an evaporator, which constitute a coolant circuit where a non-azeotropic mixed coolant is circulated; and the non-azeotropic mixed coolant contains a first coolant which has a carbon double bond in the molecular structure and a second coolant which has a boiling point that is lower than the boiling point of the first coolant.

Description

Refrigeration equipment

The present invention relates to a refrigeration apparatus that circulates refrigerant between a compressor, a condenser, a throttle device, and an evaporator.

One of the refrigerants for the refrigeration apparatus is R245fa. R245fa has an ozone layer depletion coefficient of zero. In addition, by using R245fa, the refrigeration apparatus can exhibit necessary and sufficient performance. Therefore, R245fa can be considered as one of ideal refrigerants, and has been widely used in the past as described in Patent Document 1, for example.

JP 2013-213592 A

However, R245fa has a relatively high global warming potential (hereinafter referred to as GWP) of 1030.

This invention is made | formed in view of such a situation, and makes it a subject to provide the freezing apparatus using a high performance refrigerant | coolant with a lower environmental load.

A refrigeration apparatus according to the present invention includes a compressor, a condenser, a throttling device, and an evaporator constituting a refrigerant circuit in which a non-azeotropic mixed refrigerant circulates, and the non-azeotropic mixed refrigerant has a carbon double structure in a molecular structure. A first refrigerant having a bond, and a second refrigerant having a boiling point lower than that of the first refrigerant.

According to the present invention, it is possible to provide a refrigeration apparatus using a high-performance refrigerant with a lower environmental load.

The refrigerant circuit of the freezing apparatus which concerns on one Embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, embodiment described below is an example and this invention is not limited by this embodiment.

FIG. 1 shows an example of a refrigerant circuit provided in the refrigeration apparatus according to the present invention. The refrigerant circuit 1 is provided in a refrigeration apparatus such as an ultra-low temperature freezer in which the internal temperature of the storage is −80 ° C. or lower, for example.

The refrigerant circuit 1 includes a first refrigerant circuit 10 and a second refrigerant circuit 20 in which refrigerant circulates independently of each other. Both the first refrigerant circuit 10 and the second refrigerant circuit 20 can be operated simultaneously. Moreover, it is also possible to operate only one of the first refrigerant circuit 10 and the second refrigerant circuit 20 for the purpose of energy saving and maintenance.

The first refrigerant circuit 10 includes a first compressor 11, a first pre-condenser 12a and a first capacitor 12b, a first flow divider 13 that separates gas and liquid, a first auxiliary pressure reducer 14, and a first cascade capacitor 15. The first decompressor 16 and the first evaporator tube 17 are provided. The above devices are connected by a predetermined pipe (first pipe) so that the refrigerant discharged from the first compressor 11 returns to the first compressor 11 again.

The first refrigerant circuit 10 includes a non-azeotropic refrigerant mixture (hereinafter simply referred to as “refrigerant”) including a first refrigerant having a relatively high boiling point and a second refrigerant having a relatively low boiling point, such as a lubricant. Enclosed with additives. The refrigerant will be described in detail later.

Further, the first refrigerant circuit 10 includes the first oil cooler 11a in the oil reservoir in the first compressor 11, and includes the first annular pipe 18 between the first pre-condenser 12a and the first oil cooler 11a.

The first compressor 11 compresses the sucked refrigerant and discharges it to the first pre-condenser 12a.

The first pre-capacitor 12a is a meandering pipe made of, for example, copper or aluminum for dissipating heat from the refrigerant discharged from the first compressor 11.

The first capacitor 12b is formed by meandering a pipe made of, for example, copper or aluminum for further dissipating the refrigerant output from the first pre-capacitor 12a.

The first pre-capacitor 12a and the first capacitor 12b are integrally formed on the same tube plate, for example. A first shared fan 19 is arranged in the vicinity of the first pre-capacitor 12a and the first capacitor 12b so that air can be simultaneously blown to the first pre-capacitor 12a and the first capacitor 12b.

The first flow divider 13 diverts the refrigerant output from the first capacitor 12b into a liquid-phase refrigerant and a gas-phase refrigerant. After the diversion, the liquid-phase refrigerant is decompressed by the first auxiliary decompressor 14 (for example, capillary tube) and then evaporated by the first outer tube 15 a of the first cascade capacitor 15.

The first cascade capacitor 15 is a double pipe made of, for example, copper or aluminum having a first outer pipe 15a and a first inner pipe 15b. The gas phase refrigerant from the first flow divider 13 flows through the first inner pipe 15b. In the first outer pipe 15a, the liquid-phase refrigerant evaporates and cools the gas-phase refrigerant flowing through the first inner pipe 15b.

The first decompressor 16 (for example, a capillary tube) decompresses the refrigerant that has been cooled by the first inner tube 15 b of the first cascade condenser 15 and turned into a liquid phase, and outputs it to the first evaporator tube 17.

The first evaporator tube 17 is a tube made of, for example, copper or aluminum for evaporating the refrigerant decompressed by the first decompressor 16, and is an inner box (not shown) that forms a cooling chamber in which an object to be cooled is disposed. ) So as to be in thermal contact with the outer surface excluding the opening.

The cooling chamber is cooled by the cooling action when the refrigerant evaporates (vaporizes) in the first evaporator tube 17. The refrigerant that has evaporated in the first evaporator pipe 17 into the vapor phase joins the previously evaporated refrigerant in the first cascade condenser 15 and is sucked into the first compressor 11 together.

The second refrigerant circuit 20 has the same configuration as the first refrigerant circuit 10. That is, the second compressor 21, the second pre-condenser 22a and the second capacitor 22b, the second shunt 23 that separates the gas and liquid, the second auxiliary decompressor 24, the second cascade capacitor 25, and the second decompressor. 26 and a second evaporator tube 27. The above devices are connected by a predetermined pipe (second pipe) so that the refrigerant discharged from the second compressor 21 returns to the second compressor 21 again. The second refrigerant circuit 20 is filled with the same refrigerant as the first refrigerant circuit 10. Note that a refrigerant different from the refrigerant sealed in the first refrigerant circuit 10 may be sealed in the second refrigerant circuit 20 as necessary.

Further, the second refrigerant circuit 20 includes a second oil cooler 21 a and a second annular pipe 28, similarly to the first refrigerant circuit 10. The second cascade capacitor 25 has a second outer tube 25a and a second inner tube 25b.

In addition, the 2nd pre capacitor | condenser 22a and the 2nd capacitor | condenser 22b are comprised integrally in the same tube board, for example. A second shared fan 29 is arranged in the vicinity of the second pre-capacitor 22a and the second capacitor 22b so that air can be simultaneously blown to the second pre-capacitor 22a and the second capacitor 22b.

Each of the first refrigerant circuit 10 and the second refrigerant circuit 20 may have an auxiliary machine (not shown) such as an oil separator. The first decompressor 16 and the second decompressor 26 may be disposed inside the first cascade capacitor 15 and the second cascade capacitor 25, respectively. In this case, the refrigerant flowing in the first cascade condenser 15 and the second cascade condenser 25 is cooled by the refrigerant flowing in the first outer pipe 15a and the second outer pipe 25a, respectively.

In the first refrigerant circuit 10, the refrigerant circulates while changing the temperature as follows. In addition, the arrow in FIG. 1 shows the circulation direction of a refrigerant | coolant.

First, the gaseous refrigerant is sucked into the first compressor 11 and compressed. At this time, the temperature of the refrigerant rises. The refrigerant discharged from the first compressor 11 is cooled by the first pre-condenser 12a and partly condensed. The refrigerant that has passed through the first pre-capacitor 12a passes through the first annular pipe 18 and then passes through the first oil cooler 11a in the first compressor 11, and at this time, the lubricating oil in the first compressor 11 and Exchange heat. The refrigerant whose temperature has increased due to this heat exchange flows into the first capacitor 12b and is cooled by the first capacitor 12b. At this time, the first refrigerant having a relatively high boiling point is condensed, and the second refrigerant having a relatively low boiling point is cooled in a gaseous state.

Subsequently, the refrigerant flows into the first flow divider 13 and is gas-liquid separated. That is, the first refrigerant that is liquid and the second refrigerant that is gas are separated from each other.

The first refrigerant flows into the first auxiliary decompressor 14 and adiabatically expands. At this time, the temperature of the first refrigerant is reduced, and a part thereof is vaporized. Subsequently, the first refrigerant flows into the first outer pipe 15a.

Further, the second refrigerant flows into the first inner pipe 15b. The second refrigerant in the first inner tube 15b exchanges heat with the first refrigerant in the first outer tube 15a and outside the first inner tube 15b, and is cooled. At this time, the first refrigerant is vaporized and the second refrigerant is liquefied.

The second refrigerant flows into the first decompressor 16 and adiabatically expands. At this time, the temperature of the second refrigerant decreases and a part thereof is vaporized. Subsequently, the second refrigerant flows into the first evaporator tube 17 and exchanges heat with the cooling chamber adjacent to the first evaporator tube 17. That is, the second refrigerant is vaporized and the cooling chamber is cooled.

The second refrigerant that has passed through the first evaporator pipe 17 flows into the first outer pipe 15a, merges with the first refrigerant, and cools the second refrigerant in the first inner pipe 15b. The refrigerant that has exited the first outer tube 15a is again sucked into the first compressor 11 and compressed.

In the second refrigerant circuit 20 as well, the refrigerant circulates while changing the temperature as in the first refrigerant circuit 10.

The requirements required for the refrigerant used in the refrigerant circuit in which the non-azeotropic refrigerant mixture circulates as in the refrigerant circuit 1 are as follows. That is, the evaporation temperature of the second refrigerant is lower than the final target temperature, for example, −80 ° C., which is the temperature of the cooling chamber, and the first refrigerant can cool such a second refrigerant. Is needed. Of course, the smaller the GWP of the refrigerant, the better.

As a result of repeating trial and error, the inventor has obtained a non-azeotropic refrigerant mixture including a first refrigerant having a carbon double bond in a molecular structure and a second refrigerant having a boiling point lower than that of the first refrigerant. The present inventors have found that such a refrigerant is suitable.

Further, it is more preferable that a chlorine atom is bonded to one carbon atom constituting the carbon double bond. The presence of such chlorine atoms improves the affinity with oil, which is a lubricant encapsulated with the refrigerant.

Also, if the carbon number of the linear structure of the first refrigerant becomes too large, the boiling point of the first refrigerant will become too high. In this case, the difference between the boiling point of the first refrigerant and the boiling point of the second refrigerant becomes large, and the first refrigerant becomes a refrigerant that is not suitable for use in a refrigerant circuit whose target temperature is, for example, −80 ° C. Therefore, the first refrigerant preferably has a molecular structure having 2 to 4 carbon atoms, and more preferably 3 or 4 carbon atoms. In addition, when the number of carbon atoms is 4, it preferably has a molecular structure having a linear structure.

Further, the non-azeotropic refrigerant mixture may further include one or more third refrigerants having a boiling point lower than that of the first refrigerant and higher than that of the second refrigerant. In this case, the third refrigerant can be cooled by the first refrigerant, and the second refrigerant can be cooled by the third refrigerant. Therefore, it is possible to cool the second refrigerant below the target temperature more reliably. In this case, the first refrigerant circuit 10 has one or more additional cascade capacitors and one or more additional pressure reducers connected in series to the first cascade capacitor 15 and the first pressure reducer 16. May be. The same applies to the second refrigerant circuit 20.

Examples of the first refrigerant include 1,2-dichloroethylene, R1233zd (E) (trans-1-chloro-3,3,3-trifluoropropene), R1224yd (Z) ((Z) -1-chloro-2 , 3,3,3-tetrafluoropropene), R1336mzz (Z) ((Z) -1,1,1,4,4,4-hexafluoro-2-butene), R1234yf (2,3,3,3) -Tetrafluoro-1-propene) and R1234ze (E) ((E) -1,3,3,3-tetrafluoropropene) can be used. Since a chlorine atom is bonded to one carbon atom constituting the carbon double bond, a type of refrigerant such as R1233zd (E) and R1224yd (Z) is particularly preferable. The first refrigerant may be a mixture of the plurality of refrigerants listed above (for example, 1,2-dichloroethylene and R1336mzz (Z)).

Note that the boiling point and GWP of R1233zd (E) are 19 ° C. and 4.5, respectively. The boiling point and GWP of R1224yd (Z) are 15 ° C. and 1, respectively. The boiling point and GWP of R1336mzz (Z) are 33 ° C. and 9, respectively. The boiling point and GWP of R1234yf are −29 ° C. and 4, respectively. The boiling point and GWP of R1234ze (E) are -18.95 ° C. and 7, respectively.

Examples of the second refrigerant include R600 (normal butane), R290 (propane), R32 (difluoromethane), R125 (pentafluoroethane), R23 (trifluoromethane), R508A (39% by mass of trifluoromethane and hexafluoroethane 61). Azeotropic mixture), R508B (mixture of 46% by mass of trifluoromethane and 54% by mass of hexafluoroethane), R170 (ethane), R744 (carbon dioxide), R14 (carbon tetrafluoride), R50 (Methane) and argon can be used. Further, as the second refrigerant, a substance having a double bond in the structure such as R1270 (propylene) or R1150 (ethylene) may be used.

Note that the boiling point and GWP of R600 are −0.55 ° C. and 4, respectively. The boiling point and GWP of R290 are −42.09 ° C. and 3, respectively. The boiling point and GWP of R32 are −51.651 ° C. and 675, respectively. The boiling point and GWP of R1270 are −47.69 ° C. and 2, respectively. The boiling point and GWP of R125 are −48.09 ° C. and 3500, respectively. The boiling point and GWP of R23 are −82.1 ° C. and 14800, respectively. The boiling point and GWP of R508A are −87.377 ° C. and 13214, respectively. The boiling point and GWP of R508B are −87.344 ° C. and 13396, respectively. The boiling point and GWP of R170 are −88.598 ° C. and 6, respectively. The boiling point and GWP of R744 are −78.4 ° C. and 1, respectively. The boiling point and GWP of R14 are −128.05 ° C. and 7390, respectively. The boiling point and GWP of R1150 are −104 ° C. and 4, respectively. The boiling point and GWP of R50 are −161.48 ° C. and 25, respectively. The boiling point and GWP of argon are −185.85 ° C. and 0, respectively.

Further, the non-azeotropic refrigerant mixture may include a plurality of types of refrigerants listed above as the second refrigerant. In that case, the refrigerant having the lower boiling point is the second refrigerant, and the refrigerant having the higher boiling point is the third refrigerant. For example, R23, R508A, R508B, R170, R744, R14, R1150, or R50 can be the second refrigerant, and R600, R290, R32, R1270, or R125 can be the third refrigerant. Of course, a plurality of types of the second refrigerant and the third refrigerant may be included.

Further, the non-azeotropic refrigerant mixture may include a plurality of types of refrigerants listed above as the first refrigerant. In that case, the refrigerant having the higher boiling point is the first refrigerant, and the refrigerant having the lower boiling point is the second refrigerant. For example, 1,2-dichloroethylene, R1233zd (E), R1224yd (Z), or R1336mzz (Z) can be the first refrigerant, and R1234yf or R1234ze (E) can be the second refrigerant.

Further, the non-azeotropic refrigerant mixture may include a total of three or more types of refrigerants listed above as the first refrigerant and those listed as the second refrigerant above. In that case, the refrigerant having the higher boiling point is the first refrigerant, the refrigerant having the lower boiling point is the second refrigerant, and the refrigerant having the intermediate boiling point is the third refrigerant. For example, 1,2-dichloroethylene, R1233zd (E), R1224yd (Z) or R1336mzz (Z) is the first refrigerant, and R23, R508A, R508B, R170, R744, R14, R1150, R50, R600, R290, R32, R1270 or R125 can be the second refrigerant, and R1234yf or R1234ze (E) can be the third refrigerant.

Subsequently, an experiment performed using an ultra-low temperature freezer equipped with the refrigerant circuit 1 will be described. In the experiment, various refrigerants shown in Table 1 were used as the refrigerant sealed in the first refrigerant circuit 10. In addition, the refrigerant | coolant 1 is a control | contrast and is a refrigerant | coolant which contains R245fa used conventionally as a 1st refrigerant | coolant.

Further, as the refrigerant sealed in the second refrigerant circuit 20, the refrigerant 1 (control) in Table 1 was always used regardless of the refrigerant sealed in the first refrigerant circuit 10.

In the experiment, the temperature at the inlet and outlet of the first evaporator tube 17 was measured. The measurement results are also shown in Table 1. The temperature around the ultra-low temperature freezer at the time of the experiment was 30 ° C.

As shown in Table 1, when the conventionally used refrigerant 1 containing R245fa (control) was used, both the inlet temperature and the outlet temperature of the first evaporator tube 17 were lower than -80 ° C. . That is, the temperature in the cooling chamber was sufficiently low.

Further, when the refrigerant 2 is different from that of the refrigerant 1 in that it includes R1233zd (E) instead of R245fa, the inlet temperature and the outlet temperature of the first evaporator pipe 17 are the same as when the refrigerant 1 is used. It became almost the same value. That is, the temperature in the cooling chamber was sufficiently low.

In addition, when the refrigerant 3 is different from the refrigerant 2 in that the content ratio of R1233zd (E) is high and the content ratio of R600 is low, the inlet temperature and the outlet temperature of the first evaporator pipe 17 are used. Were slightly higher than when the refrigerant 1 was used. However, both temperatures were well below -80 ° C. That is, the temperature in the cooling chamber was sufficiently low.

In addition, in comparison with the refrigerant 2 and the refrigerant 3, when the refrigerant 4 which does not include R600 and is different in that it includes a lot of R1233zd (E), the inlet temperature and the outlet temperature of the first evaporator pipe 17 are Compared with the case where the refrigerant | coolant 1 was used, each became a little high. However, both temperatures were well below -80 ° C. That is, the temperature in the cooling chamber was sufficiently low.

In addition, when the refrigerant 5 is different from the refrigerant 4 in that it includes R1234ze (E) instead of R1233zd (E), the refrigerant 1 is used as the inlet temperature and the outlet temperature of the first evaporator tube 17. Compared with the case where it was, each became slightly high. However, both temperatures were well below -80 ° C. That is, the temperature in the cooling chamber was sufficiently low.

In addition, when the refrigerant 6 different from the refrigerant 2 in that it includes R290 instead of R600, the inlet temperature and the outlet temperature of the first evaporator pipe 17 are lower than when the refrigerant 1 is used. . That is, the refrigerant 6 is a refrigerant having a higher refrigeration capacity than the refrigerant 1. And since all the refrigerant | coolants contained in the refrigerant | coolant 6 have small GWP, the refrigerant | coolant 6 is excellent also from a viewpoint that an environmental load is small.

In addition, when the refrigerant 7 is different from that of the refrigerant 2 in that it includes R170 instead of R23 and R14, the inlet temperature and the outlet temperature of the first evaporator pipe 17 are compared with those when the refrigerant 1 is used. And each increased slightly. However, both temperatures were well below -80 ° C. That is, the temperature in the cooling chamber was sufficiently low. And since all the refrigerant | coolants contained in the refrigerant | coolant 7 have small GWP, the refrigerant | coolant 7 is excellent also from a viewpoint that an environmental load is small.

Also, compared to the refrigerant 7, when the refrigerant 8 different in further including R50 was used, the inlet temperature of the first evaporator tube 17 was lower than when the refrigerant 1 was used. That is, the refrigerant 8 is a refrigerant having a higher refrigeration capacity than the refrigerant 1. And since all the refrigerant | coolants contained in the refrigerant | coolant 8 have small GWP, the refrigerant | coolant 8 is excellent also from a viewpoint that an environmental load is small.

In addition, it cannot be overemphasized that a various deformation | transformation and application are possible for this invention in the range which is not limited to embodiment described previously and does not deviate from the summary.

For example, the refrigeration apparatus according to the present invention is not limited to the ultra-low temperature freezer, and may be a refrigeration apparatus such as a biomedical freezer, a showcase, a freezer / refrigerated warehouse, a cold storage car, or an ice maker. Further, the obtained cooling temperature may be higher than −80 ° C., for example, −40 ° C., or may be an extremely low temperature of −150 ° C. or lower of −80 ° C. or lower.

Further, the refrigerant circuit included in the refrigeration apparatus according to the present invention is not limited to the refrigerant circuit 1 shown in FIG. 1, and may include only the first refrigerant circuit 10, for example.

Further, the refrigeration apparatus according to the present invention may include a binary refrigerant circuit. In the binary refrigerant circuit, two types of refrigerants having different boiling points are circulated in independent refrigerant circuits, and these two types of refrigerants are subjected to heat exchange via a cascade heat exchanger, for example, at −150 ° C. It is a refrigerant circuit for obtaining the following cryogenic temperature.

Of course, one or both of the refrigerant circuits constituting the binary refrigerant circuit may have the same configuration as the first refrigerant circuit 10 shown in FIG.

The disclosure of the specification, claims, drawings and abstract contained in the Japanese application of Japanese Patent Application No. 2018-028240 filed on February 20, 2018 is incorporated herein by reference.

The present invention is suitably used as a refrigeration apparatus capable of obtaining extremely low temperatures.

DESCRIPTION OF SYMBOLS 1 Refrigerant circuit 10 1st refrigerant circuit 11 1st compressor 11a 1st oil cooler 12a 1st precondenser 12b 1st capacitor | condenser 13 1st shunt 14 14 1st auxiliary pressure reducer 15 1st cascade condenser 15a 1st outer tube 15b 1st 1 inner pipe 16 first decompressor 17 first evaporator pipe 18 first annular pipe 19 first shared fan 20 second refrigerant circuit 21 second compressor 21a second oil cooler 22a second pre-condenser 22b second condenser 23 second 2 shunt 24 Second auxiliary pressure reducer 25 Second cascade condenser 25a Second outer pipe 25b Second inner pipe 26 Second pressure reducer 27 Second evaporator pipe 28 Second annular pipe 29 Second shared fan

Claims

A compressor, a condenser, a throttling device and an evaporator constituting a refrigerant circuit in which a non-azeotropic refrigerant mixture circulates;
The non-azeotropic refrigerant mixture includes a first refrigerant having a carbon double bond in a molecular structure, and a second refrigerant having a boiling point lower than that of the first refrigerant.
Refrigeration equipment.
A chlorine atom is bonded to one carbon atom constituting the carbon double bond,
The refrigeration apparatus according to claim 1.
The molecular structure has a linear structure having 3 to 4 carbon atoms,
The refrigeration apparatus according to claim 1 or 2.
The boiling point of the second refrigerant is −80 ° C. or lower.
The refrigeration apparatus according to any one of claims 1 to 3.
The non-azeotropic refrigerant mixture further includes a third refrigerant having a boiling point lower than the boiling point of the first refrigerant and higher than the boiling point of the second refrigerant.
The refrigeration apparatus according to any one of claims 1 to 4.