REEFER CONTAINER

Description

TECHNICAL FIELD

The present disclosure relates to a reefer container.

The present application claims priority based on Japanese Patent Application No. 2021-210499 filed on Dec. 24, 2021, the entire content of which is incorporated herein by reference.

BACKGROUND ART

A reefer container is a container having a refrigeration function to freeze or refrigerate goods such as cargo stored in the container.

Patent Document 1 discloses a reefer container in which an air passage is provided inside the container for circulating air inside the container, and the air flowing through the air passage is cooled by heat exchange in an evaporator. In the air passage inside the container, the above-described evaporator, which constitutes a closed-cycle refrigerator, and a fan and fan motor for circulating the air inside the container are arranged.

CITATION LIST

Patent Literature

Patent Document 1: JPH09-210534A

SUMMARY

Problems to Be Solved

In the reefer container described in Patent Document 1, devices (evaporator) constituting the refrigerator and devices (fan and motor) for circulating air in the container are installed inside the container, narrowing a cargo space in the container. Further, defrost operation is required to remove frost adhered to the evaporator (heat exchanger) placed inside the container, which may reduce low-temperature reliability of the cargo inside the container. Furthermore, the heating elements such as the motor are disposed inside the container, causing a hot spot or an uneven temperature inside the container.

In view of the above, an object of at least one embodiment of the present invention is to provide a reefer container capable of suppressing a reduction in cargo space inside the container and stably maintaining a temperature inside the container.

Solution to the Problems

A reefer container according to at least one embodiment of the present invention is provided with: a container body; an air refrigerant line having a suction port and a blowout port each of which is disposed inside the container body; a compressor disposed in the air refrigerant line and configured to compress air suctioned from inside the container body to the air refrigerant line through the suction port; at least one heat exchanger disposed in the air refrigerant line and configured to cool the air compressed by the compressor; and a turbine disposed between the at least one heat exchanger and the blowout port in the air refrigerant line and configured to expand the air cooled by the at least one heat exchanger. The air refrigerant line includes: a suctioned air line for directing the air suctioned from the suction port to the compressor; a compressed air line for directing the air compressed by the compressor to the turbine; and an expanded air line for directing the air expanded by the turbine to the blowout port. The compressor, the at least one heat exchanger, and the turbine are disposed, in an exterior space of the container body, along a partition wall that separates an interior space of the container body and the exterior space.

Advantageous Effects

At least one embodiment of the present invention provides a reefer container capable of suppressing a reduction in cargo space inside the container and stably maintaining a temperature inside the container.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic perspective view of a reefer container according to some embodiments.

FIG. 2 is a schematic perspective view of the reefer container shown in FIG. 1, as seen in another direction.

FIG. 3 is a diagram schematically showing a circuit of a refrigerator of the reefer container according to an embodiment.

FIG. 4 is a view of the reefer container according to an embodiment, as seen in the direction of arrow A in FIG. 2.

FIG. 5 is a view of the reefer container shown in FIG. 4, as seen in the direction of arrow B in FIG. 2.

FIG. 6 is a view of the reefer container according to an embodiment, as seen in the direction of arrow A in FIG. 2.

FIG. 7 is a view of the reefer container shown in FIG. 6, as seen in the direction of arrow B in FIG. 2.

FIG. 8 is a side view of the reefer container 100 according to an embodiment.

FIG. 9 is a diagram schematically showing the circuit of the refrigerator of the reefer container according to an embodiment.

FIG. 10 is a diagram schematically showing the circuit of the refrigerator of the reefer container according to an embodiment.

DETAILED DESCRIPTION

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It is intended, however, that unless particularly identified, dimensions, materials, shapes, relative positions, and the like of components described in the embodiments shall be interpreted as illustrative only and not intended to limit the scope of the present invention.

Configuration of Reefer Container

FIG. 1 is a schematic perspective view of a reefer container according to some embodiments. FIG. 2 is a schematic perspective view of the reefer container shown in FIG. 1, as seen in another direction, and shows the interior of the container by omitting several walls of the reefer container.

As shown in FIGS. 1 and 2, the reefer container 100 includes a container body 1 that can accommodate goods such as cargo. The container body 1 has a ceiling wall 4, a bottom wall 5, a pair of short lateral walls 6, 7, and a pair of long lateral walls 8, 9. These walls separate an interior space 2 from an exterior space 3 of the container body 1.

The container body 1 may be a shipping container used to transport cargo, etc. The container body 1 may be a standard shipping container such as a 20 ft container or a 40 ft container.

FIG. 3 is a diagram schematically showing a circuit of a refrigerator (refrigeration cycle) of the reefer container according to an embodiment. FIGS. 4 and 6 are each a view of the reefer container according to an embodiment, as seen in the direction of arrow A in FIG. 2 (longitudinal direction of container body 1). FIGS. 5 and 7 are each a view of the reefer container shown in FIGS. 4 and 6, respectively, as seen in the direction of arrow B in FIG. 2 (opposite direction from FIGS. 4 and 6) from inside the container body 1.

As shown in FIGS. 2 to 5, the interior space 2 of the container body 1 is provided with a blowout portion 14 including a blowout port 16 (opening) for blowing air to the interior of the container body 1, and a suction portion 18 including a suction port 20 for suctioning air inside the container body 1. In FIGS. 3 and 5, the blowout portion 14 and the suction portion 18 are not illustrated.

As shown in FIGS. 3 to 5, the reefer container 100 includes an air refrigerant line 22 having the suction port 20 and the blowout port 16 which are described above, and a compressor 24, at least one heat exchanger 32, and a turbine 26 each of which are disposed in the air refrigerant line 22.

The air refrigerant line 22 is a passage extending from the suction port 20 to the blowout port 16, and allows the air suctioned from inside the container body 1 through the suction port 20 to flow. The compressor 24 is configured to compress the air suctioned to the air refrigerant line 22 through the suction port 20. The at least one heat exchanger 32 is configured to cool the high temperature and pressure air compressed by the compressor 24. The turbine 26 is configured to expand the air cooled by the at least one heat exchanger 32. The low temperature air expanded by the turbine 26 is directed through the air refrigerant line 22 to the blowout port 16 and is blown to the interior of the container body 1 through the blowout port 16. That is, the air refrigerant line 22, the compressor 24, the at least one heat exchanger 32, and the turbine 26 configure a refrigerator (refrigeration cycle) that uses the air from inside the container body 1 as a refrigerant.

Here, the air refrigerant line 22 includes a suctioned air line 22A for directing the air suctioned from the suction port 20 to the compressor 24, a compressed air line 22B for directing the air compressed by the compressor 24 to the turbine 26, and an expanded air line 22C for directing the air expanded by the turbine 26 to the blowout port 16.

In the exemplary embodiments shown in FIGS. 3, 4 and 6, the at least one heat exchanger 32 includes a first heat exchanger 34 and a second heat exchanger 36. The first heat exchanger 34 is configured to exchange heat between the air flowing through the suctioned air line 22A and the air flowing through the compressed air line 22B. The second heat exchanger 36 is disposed upstream of the first heat exchanger 34 in the compressed air line 22B and is configured to exchange heat between the air flowing through the compressed air line toward the first heat exchanger 34 and a cooling fluid (e.g., water) other than the air flowing through the air refrigerant line 22.

In the compressed air line 22B, the high temperature and pressure air compressed by the compressor 24 is cooled by heat exchange with the cooling fluid (e.g., water) in the second heat exchanger 36, and then further cooled by heat exchange with the relatively low temperature air flowing through the cooling air line in the first heat exchanger 34.

In the exemplary embodiments shown in FIGS. 3, 4 and 6, the second heat exchanger 36 is configured to cool the air flowing through the compressed air line toward the first heat exchanger 34 by heat exchange with water. In an embodiment, as shown in FIG. 3, the second heat exchanger 36 is supplied with water through a water circulation line 38. The water circulation line 38 is provided with a radiator 40 constituting a cooling device 39 for cooling water, and a pump 42. The water increased in temperature by heat exchange with the air in the second heat exchanger 36 is cooled by the cooling device 39 including the radiator 40. The cooling device 39 also includes a fan 41 for air-cooling the radiator 40.

In some embodiments, the compressor 24 and the turbine 26 may be coupled to each other via a rotational shaft. In the exemplary embodiments shown in FIGS. 3, 4 and 6, the compressor 24 and the turbine 26 are both connected to a rotational shaft 30 which is an output shaft of a motor 28 for driving the compressor 24, and thus they are connected to each other via the rotational shaft 30.

The motor 28 is supplied with electric current from a power source (e.g., generator) which is not shown. Further, in the turbine 26, part of expansion energy generated when the air expands is recovered, and the recovered expansion energy assists in driving the compressor 24.

As shown in FIGS. 4 and 6, the suctioned air line 22A, the compressed air line 22B, and the expanded air line 22C are formed by respective pipes.

In the exemplary embodiments shown in FIGS. 4 and 6, the pipe forming the suctioned air line 22A includes a pipe 48 disposed between the suction port 20 and the inlet of the first heat exchanger 34, and a pipe 50 disposed between the outlet of the first heat exchanger 34 and the compressor 24. The pipe forming the compressed air line 22B includes a pipe 52 disposed between the outlet of the compressor 24 and the inlet of the second heat exchanger 36, a pipe 54 disposed between the outlet of the second heat exchanger 36 and the inlet of the first heat exchanger 34, and a pipe 56 disposed between the outlet of the first heat exchanger 34 and the inlet of the turbine 26. The pipe forming the expanded air line 22C includes a pipe 58 disposed between the outlet of the turbine 26 and the blowout port 16.

The respective pipes forming the air refrigerant line 22 may be a plurality of pipe portions connected via flanges, etc.

In some embodiments, as shown in FIGS. 1, 4 and 6, the compressor 24, the at least one heat exchanger 32 (first heat exchanger 34 and second heat exchanger 36 in FIGS. 4 and 6), and the turbine 26, each of which is disposed in the air refrigerant line 22, are arranged in the exterior space 3 of the container body 1 along a partition wall 10 that separates the interior space 2 and the exterior space 3 of the container body 1. In the exemplary embodiments shown in FIGS. 1, 4 and 6, the above-described devices disposed in the air refrigerant line 22 are arranged along the short lateral wall 7 as the partition wall 10. In FIG. 1, some of the above-described devices in the air refrigerant line 22 are shown schematically by the double-dotted dashed lines.

As shown in FIGS. 1, 4 and 6, a cover 12 may be provided to surround the above-described devices in the exterior space 3 of the container body 1 from above, below and from the side.

As shown in FIGS. 4 to 7, the pipe 48 between the suction port 20 and the first heat exchanger 34 may be provided through a hole 49 in the short lateral wall 7 (partition wall 10). The pipe 58 between the turbine 26 and the blowout port 16 may be provided through a hole 59 in the short lateral wall 7 (partition wall 10).

According to the above-described embodiment, the refrigerator (refrigeration cycle) including the compressor 24, the heat exchanger 32 (34, 36), and the turbine 26, which are installed in the exterior space 3 of the container body 1, and using the air inside the container body 1 as the refrigerant is constructed. Since these devices are not provided in the interior space 2 of the container body 1, it is possible to secure a wide cargo space inside the container.

Additionally, the above-described embodiment eliminates the need for a heat exchanger such as an evaporator in the interior space 2 of the container body 1, eliminating the need for defrost operation to defrost such a heat exchanger. On the other hand, the air inside the container body 1 naturally circulates from the blowout port 16 to the suction port 20 (see arrows in FIG. 2) due to a difference between the pressure in the blowout port 16 and the pressure in the suction port 20, eliminating the need for a fan for circulating the air inside the container. Therefore, there is no increase in temperature inside the container due to the installation of the fan and fan motor inside the container. Accordingly, it is easy to maintain the temperature inside the container at a desired temperature.

Additionally, according to the above-described embodiment, the devices (compressor 24, heat exchanger 32 (34, 36), and turbine 26) constituting the refrigerator are installed in a relatively narrow space along the partition wall 10 in the exterior space 3 of the container body 1. Thus, since the installation area for the refrigerator added to the container body 1 is small, the reefer container 100 including this refrigerator can be appropriately used as a container for transportation and other purposes.

Therefore, according to the above-described embodiment, it is possible to obtain the reefer container 100 capable of suppressing a reduction in cargo space inside the container and stably maintaining the temperature inside the container.

In some embodiments, a motor usable at a rotation speed of 50,000 rpm or higher is used as the motor (e.g., motor 28 described above) for driving the compressor 24. The motor may be an inverter motor.

By using the motor usable at a high speed of 50,000 rpm, a relatively small compressor and turbine can be employed. Thus, the size and weight of the devices constituting the refrigerator can be reduced.

In some embodiments, at least two of the compressor 24, the at least one heat exchanger 32, and the turbine 26 are arranged in the up-down direction. In other words, at least two of the aforementioned are displaced from each other in the up-down direction.

For example, in the exemplary embodiments shown in FIGS. 4 and 6, the first heat exchanger 34 (heat exchanger 32) and a combination of the compressor 24 and the turbine 26 are arranged in the up-down direction. Further, the second heat exchanger 36 (heat exchanger 32) and a combination of the compressor 24 and the turbine 26 are arranged in the up-down direction. Further, the first heat exchanger 34 (heat exchanger 32) and the second heat exchanger 36 (heat exchanger 32) are arranged in the up-down direction.

In the above-described embodiment, since at least two of the compressor 24, the at least one heat exchanger 32, and the turbine 26 constituting the refrigerator are arranged in the up-down direction, the installation area for the devices in the exterior space 3 of the container body 1 can be reduced. In other words, the installation area for the refrigerator added to the container body 1 can be reduced.

As described above, in the exemplary embodiments shown in FIGS. 4 and 6, the first heat exchanger 34 and the second heat exchanger 36 are arranged in the up-down direction.

In the above-described embodiment, since the first heat exchanger 34 and the second heat exchanger 36, which are relatively large-sized among the devices constituting the refrigerator, are arranged in the up-down direction, the installation area for the devices in the exterior space 3 of the container body 1 can be reduced effectively. In other words, the installation area for the refrigerator added to the container body 1 can be reduced.

In the exemplary embodiments shown in FIGS. 4 and 6, the first heat exchanger 34 is disposed above the second heat exchanger 36 in the up-down direction.

Generally, the suction port 20 is disposed above the blowout port 16 inside the container body 1. In this regard, in the above-described embodiment, since the first heat exchanger 34 is in a relatively high position, the pipe 48 between the suction port 20 in the container and the first heat exchanger 34 can be relatively shortened. As a result, heat input to the refrigerant (air) from the outside air or the like through this pipe is suppressed, and the efficiency of the refrigeration cycle is improved.

FIG. 8 is a side view of the reefer container 100 according to an embodiment.

In the above-described embodiment, since the second heat exchanger 36 is in a relatively low position, even when using a generator 60 that is suspended from the edge of the container ceiling, for example as shown in FIG. 8, the second heat exchanger 36 and the cooling device 39 used with the second heat exchanger 36 and the generator 60 can be arranged so that they do not overlap when viewed from a direction perpendicular to the partition wall 10 (in FIG. 8, the same direction as longitudinal direction of container body 1). Therefore, the operation of the cooling device 39 (e.g., fan 41, etc.) is less likely to be interfered with by the generator 60.

In the exemplary embodiment shown in FIG. 6, the compressor 24 and the turbine 26 are disposed between the first heat exchanger 34 and the second heat exchanger 36 in the up-down direction.

According to the above-described embodiment, in the up-down direction, since the first heat exchanger 34, the second heat exchanger 36, and a combination of the compressor 24 and the turbine 26 are arranged in the up-down direction, the installation area for the devices in the exterior space 3 of the container body 1 can be further reduced.

Additionally, in the above-described embodiment, since the compressor 24 and the turbine 26 are disposed between the first heat exchanger 34 and the second heat exchanger 36, the length of the pipe (e.g., pipe 52 or pipe 56, etc.) connecting the first heat exchanger 34 or the second heat exchanger 36 to the compressor 24 or the turbine 26 can be easily shortened. As a result, heat input to the refrigerant (air) from the outside air or the like through these pipes is suppressed. On the other hand, since the pipe 52 through which the relatively high temperature air flows between the outlet of the compressor 24 and the second heat exchanger 36 can be shortened, it is possible to suppress heating of the refrigerant through surrounding pipes and devices due to heat dissipation from the pipe 52. As a result, the efficiency of the refrigeration cycle is improved.

In some embodiments, the at least one heat exchanger 32 (first heat exchanger 34 and/or second heat exchanger 36) may include a plate heat exchanger or a microchannel heat exchanger. In particular, if the at least one heat exchanger 32 includes a plurality of heat exchangers (first heat exchanger 34 and second heat exchanger 36) arranged in the up-down direction, one heat exchanger 32 (first heat exchanger 34 in the examples shown in FIGS. 4 and 6) in a higher position may include a plate heat exchanger or a microchannel heat exchanger. The plate heat exchanger or microchannel heat exchanger may be made of materials containing aluminum or titanium.

In the above-described embodiment, at least one heat exchanger 32 is a relatively lightweight heat exchanger such as a plate heat exchanger or a microchannel heat exchanger. Accordingly, the heat exchanger can be installed on a wall surface and is easy to install in a higher position. This makes it easier to arrange the heat exchanger and the other devices in the up-down direction, facilitating a reduction in the installation area for the devices in the exterior space 3 of the container body 1.

Here, the partition wall 10 has a first end 62 and a second end 64 which are opposite ends in the horizontal direction. In the examples shown in FIGS. 4 to 7, of the two ends of the partition wall 10 in the horizontal direction, the end closer to the long lateral wall 9 of the container body 1 is the first end 62, and the end closer to the long lateral wall 8 is the second end 64.

In some embodiments, for example as shown in FIG. 6, the first heat exchanger 34 and the compressor 24 and the turbine 26, which are connected to each other via the rotational shaft 30 extending along the horizontal direction, are arranged in the up-down direction. Further, the inlet of the first heat exchanger 34 in the compressed air line 22B is disposed closer to the second end 64 than the outlet of the first heat exchanger 34 in the compressed air line 22B in the horizontal direction, and the turbine 26 is disposed closer to the first end 62 than the compressor 24 in the horizontal direction. In FIG. 6, the inlet of the first heat exchanger 34 in the compressed air line 22B is the connection between the first heat exchanger 34 and the pipe 54. Further, the outlet of the first heat exchanger 34 in the compressed air line 22B is the connection between the first heat exchanger 34 and the pipe 56.

According to the above-described embodiment, the first heat exchanger 34 and the compressor 24 and the turbine 26 that shares the rotational shaft 30 are arranged in the up-down direction, and in the horizontal direction, the outlet of the first heat exchanger 34 in the compressed air line 22B and the turbine 26 are disposed closer to the first end 62. Accordingly, the length of the pipe 56 forming the compressed air line 22B between the outlet of the first heat exchanger 34 and the inlet of the turbine 26 can be easily shortened. As a result, heat input to the refrigerant (air) from the outside air or the like through the pipe 56 is suppressed, and the efficiency of the refrigeration cycle is improved.

In some embodiments, for example as shown in FIG. 6, the length of the pipe 52 forming a portion of the compressed air line 22B between the outlet of compressor 24 and the second heat exchanger 36 is shorter than the length of the pipe 50 forming a portion of the suctioned air line 22A between the first heat exchanger 34 and the inlet of the compressor 24.

In this case, since the pipe 52 through which the relatively high temperature air flows between the outlet of the compressor 24 and the second heat exchanger 36 is relatively short, it is possible to suppress heating of the refrigerant through surrounding pipes and devices due to heat dissipation from the pipe 52. As a result, the efficiency of the refrigeration cycle is improved.

In some embodiments, for example as shown in FIG. 6, the compressor 24 and the turbine 26 are disposed between the first heat exchanger 34 and the second heat exchanger 36 in the up-down direction. Further, of both end portions of the second heat exchanger 36 in the horizontal direction, an end portion closer to the second end 64 of the partition wall 10 is connected to the pipe 52 forming a portion of the compressed air line 22B between the compressor 24 and the second heat exchanger 36.

According to the above-described embodiment, in the horizontal direction, among the compressor 24 and the turbine 26, the compressor 24 is disposed closer to the second end 64, and the pipe 52 forming a portion of the compressed air line 22B between the outlet of the compressor 24 and the second heat exchanger 36 is connected to the end portion of the second heat exchanger 36 closer to the second end 64. Accordingly, the pipe 52 through which the relatively high temperature air flows can be easily shortened. Thus, it is possible to suppress heating of the refrigerant through surrounding pipes and devices due to heat dissipation from the pipe 52. As a result, the efficiency of the refrigeration cycle is improved.

As shown in FIG. 6, the cooling device 39 (radiator 40 and/or fan 41, etc.) for cooling the cooling fluid to be supplied to the second heat exchanger 36 may be disposed closer to the second end 64 of the partition wall 10 than the second heat exchanger 36 in the horizontal direction. Further, the pipe for supplying the cooling fluid from the cooling device 39 to the second heat exchanger 36 (in the illustrated embodiment, pipe forming water circulation line 38) may be connected to the end portion of the second heat exchanger 36 closer to the second end 64. By concentrating the pipes connected to the second heat exchanger 36 on the second end 64 side, the second heat exchanger 36 and the cooling device 39 can be easily arranged in the horizontal direction side by side within a narrow installation space.

In some embodiments, for example as shown in FIGS. 4 to 7 (especially FIGS. 5 and 7), a portion of the pipe 58 forming the expanded air line 22C between the outlet of the turbine 26 and the blowout port 16 is exposed to the interior space 2 of the container body 1.

In the above-described embodiment, since a portion of the pipe 58 through which the low-temperature air flows between the outlet of the turbine 26 and the blowout port 16 is exposed to the interior space 2 of the container body 1, the portion of the pipe 58 that is placed in the exterior space 3 can be shortened. As a result, heat input to the refrigerant (air) from the outside air or the like through the pipe 58 is suppressed, and the efficiency of the refrigeration cycle is improved.

In some embodiments, the length H1 of the portion of the pipe 58 forming the expanded air line 22C that is exposed to the interior space 2 of the container body 1 may be not less than half the height H0 of the container body 1 (i.e., not less than H0/2) (see FIGS. 5 and 7).

In the above-described embodiment, since the length H1 of the pipe 58 through which the low temperature air flows between the outlet of the turbine 26 and the blowout port 16 is not less than H0/2 and relatively long, the portion of the pipe 58 that is placed in the exterior space 3 can be shortened. As a result, heat input to the refrigerant (air) from the outside air or the like through the pipe 58 is suppressed.

In some embodiments, the blowout port 16 (see FIGS. 5 and 7) has an opening that is larger in size than the inner diameter of the pipe 58 forming the expanded air line 22C. For example, the equivalent diameter of the blowout port 16 (opening) is larger than the inner diameter of the pipe 58.

According to the above-described embodiment, the blowout port 16 for blowing the air expanded by the turbine 26 into the interior space 2 of the container body 1 is larger in size than the inner diameter of the pipe 58 forming the expanded air line 22C. Therefore, even if moisture in the air freezes in the turbine and frost occurs, the frost that reaches the blowout port from the pipe is prevented from accumulating in the blowout port, and the frost can be easily discharged along with the air from the blowout port. Thus, the pressure loss due to frost accumulation at the turbine outlet is reduced, so that the efficiency of the refrigeration cycle is improved.

In some embodiments, a filter part 21 is disposed at the suction port 20 for removing foreign matters. The filter part 21 includes a material with a plurality of holes or mesh, for example, and has a plurality of openings formed by these holes or mesh. The size (e.g., equivalent diameter) of the plurality of openings in the filter part 21 is smaller than the inner diameter of the pipe 58 forming the expanded air line 22C. Alternatively, the size of the opening of the suction port 20 may be smaller than the size of the opening of the blowout port 16.

According to the above-described embodiment, since the filter part 21 having a plurality of openings that are smaller in size than the inner diameter of the pipe 58 forming the expanded air line 22C is disposed at the suction port 20, it is possible to effectively prevent foreign matters from entering the air refrigerant line 22 through the suction port 20.

In some embodiments, as shown in FIG. 1, the partition wall 10 (in the example shown in FIG. 1, short lateral wall 7 of container body 1) that separates the interior space 2 of the container body 1 from the area where the compressor 24, the heat exchanger 32, and the turbine 26 are installed outside the container body 1 extends along a plane perpendicular to the longitudinal direction of the container body 1.

In the above-described embodiment, the devices (compressor 24, heat exchanger 32 (34, 36), and turbine 26) constituting the refrigerator are installed in a relatively narrow space along the partition wall 10 (short lateral wall 7), which is a relatively small wall extending along a plane perpendicular to the longitudinal direction of the container body 1. Thus, the installation area for the refrigerator added to the container body 1 is reduced, so that the reefer container 100 including this refrigerator can be appropriately used as a container for transportation and other purposes.

In an embodiment, the compressor 24, the at least one heat exchanger 32, and the turbine 26 may be disposed in the exterior space 3 within a range such that length L1 from the partition wall 10 in the longitudinal direction of the container body 1 is 1/10 or less of length L0 of the container body 1 (see FIG. 1).

In this case, the installation area for the devices constituting the refrigerator is within 1/10 or less of length L0 of the container body. Thus, since the installation area for the refrigerator added to the container body 1 is small, the reefer container 100 including this refrigerator can be appropriately used as a container for transportation and other purposes.

For example, if the container body is a 20 ft container (length L0: approx. 6.1 m, width W0: approx. 2.4 m, height H0: approx. 2.6 m), the length (L1) of the installation area may be 610 mm or less.

FIGS. 9 and 10 are each a diagram schematically showing the circuit of the refrigerator (refrigeration cycle) of the reefer container 100 according to an embodiment. The embodiments shown in FIGS. 9 and 10 is the same as the embodiment shown in FIG. 3 except the following description.

In the exemplary embodiment shown in FIG. 9, the reefer container 100 includes a circulation line 44 for circulating part of the air flowing through the compressed air line 22B to the inlet of the compressor 24. In the example shown in FIG. 9, the circulation line 44 is provided with a valve 45 for regulating the flow rate of the air circulated through the circulation line 44 to the inlet of the compressor 24.

In the exemplary embodiment shown in FIG. 10, the reefer container 100 includes a discharge line 46 for discharging part of the air flowing through the compressed air line 22B out of the air refrigerant line 22. In the example shown in FIG. 10, the discharge line 46 is provided with a valve 47 for regulating the flow rate of the air discharged out of the air refrigerant line 22 through the discharge line 46.

In these embodiments, even when the rotation speed of the compressor 24 is changed to adjust the output of the refrigeration cycle or for other purposes, the flow rate of the air flowing through the air refrigerant line 22 can be properly regulated according to the rotation speed of the compressor 24. Thus, the refrigerator can be operated appropriately.

The contents described in the above embodiments would be understood as follows, for instance.

• • (1) A reefer container (100) according to at least one embodiment of the present invention is provided with: a container body (1); an air refrigerant line (22) having a suction port (20) and a blowout port (16) each of which is disposed inside the container body; a compressor (24) disposed in the air refrigerant line and configured to compress air suctioned from inside the container body to the air refrigerant line through the suction port; at least one heat exchanger (32) disposed in the air refrigerant line and configured to cool the air compressed by the compressor; and a turbine (26) disposed in the air refrigerant line and configured to expand the air cooled by the at least one heat exchanger. The air refrigerant line includes: a suctioned air line (22A) for directing the air suctioned from the suction port to the compressor; a compressed air line (22B) for directing the air compressed by the compressor to the turbine; and an expanded air line (22C) for directing the air expanded by the turbine to the blowout port. The compressor, the at least one heat exchanger, and the turbine are disposed, in an exterior space (3) of the container body, along a partition wall (10) that separates an interior space (2) of the container body and the exterior space.

According to the above configuration (1), the refrigerator (refrigeration cycle) including the compressor, the heat exchanger, and the turbine, which are installed in the exterior space of the container body, and using the air inside the container body (air inside container) as the refrigerant is constructed. Since these devices are not provided in the interior space of the container body, it is possible to secure a wide cargo space inside the container.

Additionally, the above configuration (1) eliminates the need for a heat exchanger such as an evaporator in the interior space of the container body, eliminating the need for defrost operation to defrost such a heat exchanger. On the other hand, the air inside the container body naturally circulates from the blowout port to the suction port due to a difference between the pressure in the blowout port and the pressure in the suction port, eliminating the need for a fan for circulating the air inside the container. Therefore, there is no increase in temperature inside the container due to the installation of the fan and fan motor inside the container. Accordingly, it is easy to maintain the temperature inside the container at a desired temperature.

Additionally, according to the above configuration (1), the devices constituting the refrigerator are installed in a relatively narrow space along the partition wall in the exterior space of the container body. Thus, since the installation area for the refrigerator added to the container body is small, the reefer container including this refrigerator can be appropriately used as a container for transportation and other purposes.

Therefore, with the above configuration (1), it is possible to obtain the reefer container capable of suppressing a reduction in cargo space inside the container and stably maintaining the temperature inside the container.

• • (2) In some embodiments, in the above configuration (1), at least two of the compressor, the at least one heat exchanger, and the turbine are arranged in an up-down direction.

With the above configuration (2), since at least two of the compressor, the at least one heat exchanger, and the turbine constituting the refrigerator are arranged in the up-down direction, the installation area for the devices in the exterior space of the container body can be reduced. In other words, the installation area for the refrigerator added to the container body can be reduced.

• • (3) In some embodiments, in the above configuration (1) or (2), the at least one heat exchanger includes: a first heat exchanger (34) for exchanging heat between the air flowing through the suctioned air line and the air flowing through the compressed air line; and a second heat exchanger (36) for exchanging heat between the air flowing through the compressed air line toward the first heat exchanger and a cooling fluid other than the air flowing through the air refrigerant line. The first heat exchanger and the second heat exchanger are arranged in the up-down direction.

With the above configuration (3), since the first heat exchanger and the second heat exchanger, which are relatively large-sized among the devices constituting the refrigerator, are arranged in the up-down direction, the installation area for the devices in the exterior space of the container body can be reduced effectively. In other words, the installation area for the refrigerator added to the container body can be reduced.

• • (4) In some embodiments, in the above configuration (3), the first heat exchanger is disposed above the second heat exchanger in the up-down direction.

Generally, the suction port is disposed above the blowout port inside the container body. In this regard, in the above configuration (4), since the first heat exchanger is in a relatively high position, the pipe (pipe forming air refrigerant line) between the suction port in the container and the first heat exchanger can be relatively shortened. As a result, heat input to the refrigerant (air) through this pipe is suppressed, and the efficiency of the refrigeration cycle is improved.

Additionally, in the above configuration (4), since the second heat exchanger is in a relatively low position, even when using a generator that is suspended from the edge of the container ceiling, the second heat exchanger and the cooling device used with this heat exchanger and the generator can be arranged so that they do not overlap. Therefore, the operation of the cooling device (e.g., fan, etc.) is less likely to be interfered with by the generator.

• • (5) In some embodiments, in the above configuration (3) or (4), the compressor and the turbine are disposed between the first heat exchanger and the second heat exchanger in the up-down direction.

With the above configuration (5), since the first heat exchanger, the second heat exchanger, and a combination of the compressor and the turbine are arranged in the up-down direction, the installation area for the devices in the exterior space of the container body can be further reduced.

Additionally, in the above configuration (5), since the compressor and the turbine are disposed between the first heat exchanger and the second heat exchanger, the length of the pipe (pipe forming air refrigerant line) connecting the first heat exchanger or the second heat exchanger to the compressor or the turbine can be easily shortened. As a result, heat input to the refrigerant (air) through these pipes is suppressed. On the other hand, since the pipe through which the relatively high temperature air flows between the outlet of the compressor and the second heat exchanger can be shortened, it is possible to suppress heating of the refrigerant through surrounding pipes and devices due to heat dissipation from the pipe. As a result, the efficiency of the refrigeration cycle is improved.

• • (6) In some embodiments, in any one of the above configurations (3) to (5), a length of a pipe (52) forming a portion of the compressed air line between the outlet of the compressor and the second heat exchanger is shorter than a length of a pipe (50) forming a portion of the suctioned air line between the first heat exchanger and the inlet of the compressor.

With the above configuration (6), since the pipe through which the relatively high temperature air flows between the outlet of the compressor and the second heat exchanger is relatively short, it is possible to suppress heating of the refrigerant through surrounding pipes and devices due to heat dissipation from the pipe. As a result, the efficiency of the refrigeration cycle is improved.

• • (7) In some embodiments, in any one of the above configurations (2) to (6), the partition wall has a first end (62) and a second end (64) in a horizontal direction. The at least one heat exchanger includes a first heat exchanger for exchanging heat between the air flowing through the suctioned air line and the air flowing through the compressed air line. The compressor and the turbine are coupled to each other via a rotational shaft (30) extending along the horizontal direction. The first heat exchanger and a combination of the compressor and the turbine are arranged in the up-down direction. An inlet of the first heat exchanger in the compressed air line is disposed closer to the second end than an outlet of the first heat exchanger in the compressed air line in the horizontal direction. The turbine is disposed closer to the first end than the compressor in the horizontal direction.

With the above configuration (7), the first heat exchanger and the compressor and the turbine that shares the rotational shaft are arranged in the up-down direction, and in the horizontal direction, the outlet of the first heat exchanger in the compressed air line and the turbine are disposed closer to the first end. Accordingly, the length of the pipe forming the compressed air line between the outlet of the first heat exchanger and the inlet of the turbine can be easily shortened. As a result, heat input to the refrigerant (air) through this pipe is suppressed, and the efficiency of the refrigeration cycle is improved.

• • (8) In some embodiments, in the above configuration (7), the at least one heat exchanger includes: the first heat exchanger; and a second heat exchanger for exchanging heat between the air flowing through the compressed air line toward the first heat exchanger and a cooling fluid other than the air flowing through the air refrigerant line. The compressor and the turbine are disposed between the first heat exchanger and the second heat exchanger in the up-down direction. Of both end portions of the second heat exchanger in the horizontal direction, an end portion closer to the second end of the partition wall is connected to a pipe (52) forming a portion of the compressed air line between the compressor and the second heat exchanger.

With the above configuration (8), in the horizontal direction, among the compressor and the turbine, the compressor is disposed closer to the second end, and the pipe forming a portion of the compressed air line between the outlet of the compressor and the second heat exchanger is connected to the end portion of the second heat exchanger closer to the second end. Accordingly, the pipe through which the relatively high temperature air flows can be easily shortened. Thus, it is possible to suppress heating of the refrigerant through surrounding pipes and devices due to heat dissipation from this pipe. As a result, the efficiency of the refrigeration cycle is improved.

• • (9) In some embodiments, in any one of the above configurations (1) to (8), a portion of a pipe (58) forming the expanded air line between an outlet of the turbine and the blowout port is exposed to the interior space of the container body.

With the above configuration (9), since a portion of the pipe (pipe forming expanded air line) through which the low-temperature air flows between the outlet of the turbine and the blowout port is exposed to the interior space of the container body, the portion of the pipe that is placed in the exterior space can be shortened. As a result, heat input to the refrigerant (air) through this pipe is suppressed, and the efficiency of the refrigeration cycle is improved.

• • (10) In some embodiments, in any of the above configurations (1) to (9), the reefer container includes a circulation line (44) for circulating part of the air flowing through the compressed air line to an inlet of the compressor, or a discharge line (46) for discharging the part of the air out of the air refrigerant line.

With the above configuration (10), even when the rotation speed of the compressor is changed, the flow rate of the air flowing through the air refrigerant line can be properly regulated according to the rotation speed of the compressor, and the refrigerator can be operated appropriately.

• • (11) In some embodiments, in any one of the above configurations (1) to (10), the reefer container includes a motor (28) for driving the compressor. The motor is usable at a rotation speed of 50,000 rpm or higher.

With the above configuration (11), since the motor usable at a high speed of 50,000 rpm is used as the motor for driving the compressor, a relatively small compressor and turbine can be employed. Thus, the size and weight of the devices constituting the refrigerator can be reduced.

• • (12) In some embodiments, in any one of the above configurations (1) to (11), the at least one heat exchanger includes a plate heat exchanger or a microchannel heat exchanger.

With the above configuration (12), the at least one heat exchanger is a relatively lightweight heat exchanger, including a plate heat exchanger or a microchannel heat exchanger. Accordingly, the heat exchanger can be installed on a wall surface and is easy to install in a higher position. This makes it easier to arrange the heat exchanger and the other devices in the up-down direction, facilitating a reduction in the installation area for the devices in the exterior space of the container body.

• • (13) In some embodiments, in any one of the above configurations (1) to (12), the partition wall extends along a plane perpendicular to a longitudinal direction of the container body. The compressor, the at least one heat exchanger, and the turbine are disposed in the exterior space within a range such that a length (L1) from the partition wall in the longitudinal direction is 1/10 or less of a length (L0) of the container body.

With the above configuration (13), the installation area for the devices constituting the refrigerator is within 1/10 or less of length of the container body. Thus, since the installation area for the refrigerator added to the container body is small, the reefer container including this refrigerator can be appropriately used as a container for transportation and other purposes.

• • (14) In some embodiments, in any one of the above configurations (1) to (13), the blowout port has an opening that is larger in size than an inner diameter of a pipe forming the expanded air line.

With the above configuration (14), the blowout port for blowing the air expanded by the turbine into the interior space of the container body is larger in size than the inner diameter of the pipe forming the expanded air line. Therefore, even if moisture in the air freezes in the turbine and frost occurs, the frost that reaches the blowout port from the pipe is prevented from accumulating in the blowout port, and the frost can be easily discharged along with the air from the blowout port. Thus, the pressure loss due to frost accumulation at the turbine outlet is reduced, so that the efficiency of the refrigeration cycle is improved.

• • (15) In some embodiments, in any one of the above configurations (1) to (14), the reefer container includes a filter part disposed at the suction port and having a plurality of openings that are smaller in size than an inner diameter of a pipe forming the expanded air line.

With the above configuration (15), since the filter part having a plurality of openings that are smaller in size than the inner diameter of the pipe forming the expanded air line is disposed, it is possible to effectively prevent foreign matters from entering the air refrigerant line through the suction port.

Embodiments of the present invention were described in detail above, but the present invention is not limited thereto, and various amendments and modifications may be implemented.

In the present specification, an expression of relative or absolute arrangement such as “in a direction”, “along a direction”, “parallel”, “orthogonal”, “centered”, “concentric” and “coaxial” shall not be construed as indicating only the arrangement in a strict literal sense, but also includes a state where the arrangement is relatively displaced by a tolerance, or by an angle or a distance whereby it is possible to achieve the same function.

For instance, an expression of an equal state such as “same” “equal” and “uniform” shall not be construed as indicating only the state in which the feature is strictly equal, but also includes a state in which there is a tolerance or a difference that can still achieve the same function.

Further, an expression of a shape such as a rectangular shape or a cylindrical shape shall not be construed as only the geometrically strict shape, but also includes a shape with unevenness or chamfered corners within the range in which the same effect can be achieved.

On the other hand, an expression such as “comprise”, “include”, and “have” are not intended to be exclusive of other components.

Reference Signs List

• • 1 Container body
  • 2 Interior space
  • 3 Exterior space
  • 4 Ceiling wall
  • 5 Bottom wall
  • 6 Short lateral wall
  • 7 Short lateral wall
  • 8 Long lateral wall
  • 9 Long lateral wall
  • 10 Partition wall
  • 12 Cover
  • 14 Blowout portion
  • 16 Blowout port
  • 18 Suction portion
  • 20 Suction port
  • 21 Filter part
  • 22 Air refrigerant line
  • 22A Suctioned air line
  • 22B Compressed air line
  • 22C Expanded air line
  • 24 Compressor
  • 26 Turbine
  • 28 Motor
  • 30 Rotational shaft
  • 32 Heat exchanger
  • 34 First heat exchanger
  • 36 Second heat exchanger
  • 38 Water circulation line
  • 39 Cooling device
  • 40 Radiator
  • 41 Fan
  • 42 Pump
  • 44 Circulation line
  • 45 Valve
  • 46 Discharge line
  • 47 Valve
  • 48 Pipe
  • 49 Hole
  • 50 Pipe
  • 52 Pipe
  • 54 Pipe
  • 56 Pipe
  • 58 Pipe
  • 59 Hole
  • 60 Generator
  • 62 First end
  • 64 Second end
  • 100 Reefer container