EP4579154A1

EP4579154A1 - Refrigerated container

Info

Publication number: EP4579154A1
Application number: EP23874570.7A
Authority: EP
Inventors: Ryo TAKATA; Kazuki Yoshida
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Ltd
Priority date: 2022-10-07
Filing date: 2023-08-30
Publication date: 2025-07-02
Also published as: EP4579154A4; CN119895214A; JP7811895B2; WO2024075440A1; JP2024055255A

Abstract

A reefer container is configured to allow cooling of an internal gas corresponding to a gas inside a container body, and comprises: the container body; a circulation line having a suction port and a blowout port each provided inside the container body; a compressor configured to compress a circulating gas corresponding to the gas suctioned into the circulation line from inside the container body through the suction port; a heat exchanger configured to cool the circulating gas compressed by the compressor; an expander configured to expand the circulating gas cooled by the heat exchanger; and a warmed gas introduction line for extracting the circulating gas higher in temperature than the internal gas from between the compressor and the heat exchanger in the circulation line and guiding the extracted circulating gas to the container body.

Description

TECHNICAL FIELD

The present disclosure relates to a reefer container configured to allow cooling of a gas inside a container body.
The present application claims the priority of Japanese Patent Application No. 2022-162030 filed on October 7, 2022 , the content of which is incorporated herein by reference.

BACKGROUND

A reefer container is a container having a refrigeration function to freeze or cold-store goods such as cargo stored in the container.
In an air-refrigerant refrigerator conventionally known, air in a cooling-required room is taken in as a refrigerant for the air-refrigerant refrigerator and the refrigerant air cooled by the refrigerator is blown directly into the cooling-required room, thereby cooling the cooling-required room (see Patent Document 1). In this refrigerator, air brought to high pressure and temperature by a compressor is cooled by a cooler and then brought to low pressure and temperature by an expander.

Citation List

Patent Literature

Patent Document 1: JP3824757B

SUMMARY

Technical Problem

While the air-refrigerant refrigerator described in Patent Document 1 is capable of performing refrigerating operation for cooling air in the cooling-required room, it does not have a function for performing warming operation for warming the air in the cooling-required room. During conveyance of a reefer container, for example, a temperature outside the container (outside air temperature) may become lower than a temperature inside the container. In this case, warming-up is required inside the container. However, installing a device in the container for performing the warming-up operation for warming the inside of the container narrows a cargo space inside the container. Meanwhile, installing the device outside the container for performing warming-up operation requires a power source, a pipe, etc. to be additionally provided for suctioning gas warmed by this device into the container. Hence, the cargo space inside the container is narrowed.
In view of the above circumstances, at least one embodiment of the present invention is intended to provide a reefer container capable of suppressing reduction in a cargo space inside a container and capable of increasing and decreasing a temperature inside the container.

Solution to Problem

A reefer container according to one embodiment of the present disclosure is a reefer container configured to allow cooling of an internal gas corresponding to a gas inside a container body, comprising:

the container body;
a circulation line having a suction port and a blowout port each provided inside the container body;
a compressor provided in the circulation line and configured to compress a circulating gas corresponding to the gas suctioned into the circulation line from inside the container body through the suction port;
a heat exchanger provided in the circulation line and configured to cool the circulating gas compressed by the compressor;
an expander provided in the circulation line and configured to expand the circulating gas cooled by the heat exchanger; and
a warmed gas introduction line for extracting the circulating gas higher in temperature than the internal gas from between the compressor and the heat exchanger in the circulation line and guiding the extracted circulating gas to the container body.

Advantageous Effects

At least one embodiment of the present disclosure provides a reefer container capable of suppressing reduction in a cargo space inside the container and capable of increasing and decreasing a temperature inside the container.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic perspective view of a reefer container according to one embodiment of the present disclosure.
FIG. 2 is a schematic perspective view of the reefer container shown in FIG. 1 viewed from a different direction.
FIG. 3 is a diagram schematically showing a circuit of a refrigerator of the reefer container according to one embodiment of the present disclosure.
FIG. 4 is a view of the reefer container according to one embodiment of the present disclosure viewed from a direction indicated by an arrow A in FIG. 2.
FIG. 5 is a view of the reefer container shown in FIG. 4 viewed from a direction indicated by an arrow B in FIG. 2.
FIG. 6 is a diagram schematically showing a circuit of the refrigerator of the reefer container according to one embodiment of the present disclosure.
FIG. 7 is a diagram schematically showing a circuit of the refrigerator of the reefer container according to one embodiment of the present disclosure.
FIG. 8 is a diagram schematically showing a circuit of the refrigerator of the reefer container according to one embodiment of the present disclosure.
FIG. 9 is a diagram schematically showing a circuit of the refrigerator of the reefer container according to one embodiment of the present disclosure.
FIG. 10 is a diagram schematically showing a circuit of the refrigerator of the reefer container according to one embodiment of the present disclosure.
FIG. 11 is a view of the reefer container according to one embodiment of the present disclosure viewed from the direction indicated by the arrow A in FIG. 2.
FIG. 12 is a diagram schematically showing a circuit of the refrigerator of the reefer container according to one embodiment of the present disclosure.
FIG. 13 is a schematic sectional view of a warmed gas flow controller of the reefer container according to one embodiment of the present disclosure.
FIG. 14 is a diagram schematically showing a circuit of the refrigerator of the reefer container according to one embodiment of the present disclosure.
FIG. 15 is a diagram schematically showing a circuit of the refrigerator of the reefer container according to one embodiment of the present disclosure.
FIG. 16 is a schematic view of a deodorizing device of the reefer container according to one embodiment of the present disclosure.

DETAILED DESCRIPTION

Some embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It is intended, however, that dimensions, materials, shapes, relative positions and the like of components described as embodiments or illustrated in the drawings shall be interpreted as illustrative only and not limitative of the scope of the present disclosure.

(Configuration of Reefer Container)

FIG. 1 is a schematic perspective view of a reefer container 100 according to one embodiment of the present disclosure. FIG. 2 is a schematic perspective view of the reefer container 100 shown in FIG. 1 viewed from a different direction. In FIG. 2, some walls forming the reefer container 100 are omitted to show the inside of the reefer container 100.
As shown in FIGS. 1 and 2, the reefer container 100 includes a container body 1 having an internal space 2 available for storing goods such as cargo therein. The reefer container 100 is configured to allow cooling of a gas such as air inside the container body 1 (namely, in the internal space 2). The container body 1 has a plurality of walls 4 to 9 forming the internal space 2. Each of the plurality of walls 4 to 9 separates the internal space 2 in the container body 1 and an external space 3 external to the container body 1. The plurality of walls 4 to 9 includes a ceiling wall 4, a bottom wall 5, a pair of short-side walls 6, 7, and a pair of long- side walls 8, 9.
The container body 1 may be a transport container used to transport cargo, etc. The container body 1 may be a standard transport container such as a 10-ft container, 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 100 according to one embodiment of the present disclosure. FIG. 4 is a view of the reefer container 100 according to one embodiment of the present disclosure viewed from a direction indicated by an arrow A in FIG. 2 (from a longitudinal direction of the container body 1). FIG. 5 is a view of the reefer container 100 shown in FIG. 4 viewed from inside the container body 1 and from a direction indicated by an arrow B in FIG. 2 (from an opposite direction to FIG. 4).
As shown in FIGS. 2 to 5, the internal space 2 in the container body 1 is provided with a blowout unit 14 including a blowout port 16 (opening) for blowing a gas such as air into the container body 1, and a suction unit 18 including a suction port 20 (opening) for suctioning the gas such as air inside the container body 1. Illustrations of the blowout unit 14 and the suction unit 18 are omitted from FIGS. 3 to 5.

(Refrigerator)

As shown in FIGS. 3 to 5, the reefer container 100 includes a circulation line 22 having the above-described suction port 20 and blowout port 16, a compressor 24, a heat exchanger 26, and an expander 28. Each of the compressor 24, the heat exchanger 26, and the expander 28 is provided in the circulation line 22. The circulation line 22, the compressor 24, the heat exchanger 26, and the expander 28 form a refrigerator (refrigeration cycle) 30 that extracts an internal gas corresponding to a gas inside the container body 1 and uses the extracted internal gas as a heating medium. The reefer container 100 is capable of adjusting the temperature of the internal gas using the refrigerator 30.
The circulation line 22 is a passage extending from the suction port 20 to the blowout port 16, and is configured to cause a circulating gas to flow therethrough corresponding to a gas suctioned from inside the container body 1 through the suction port 20. The compressor 24 is configured to compress the gas (circulating gas) suctioned from inside the container body 1 into the circulation line 22 through the suction port 20. By driving the compressor 24, the gas inside the container body 1 (internal gas) is suctioned into the circulation line 22 through the suction port 20. The circulating gas compressed by the compressor 24 is increased in temperature and pressure compared to a state before being introduced into the compressor 24 to become a high temperature and pressure gas.
The heat exchanger 26 is configured to cool the high temperature and pressure circulating gas compressed by the compressor 24. The expander 28 is configured to expand the circulating gas cooled by the heat exchanger 26. The low temperature circulating gas expanded by the expander 28 is guided along the circulation line 22 to the blowout port 16, and is blown from the circulation line 22 into the container body 1 through the blowout port 16.
The circulation line 22 includes a suctioned gas line 22A for guiding the circulating gas suctioned through the suction port 20 to the compressor 24, a compressed gas line 22B for guiding the circulating gas compressed by the compressor 24 to the expander 28, and an expanded gas line 22C for guiding the circulating gas expanded by the expander 28 to the blowout port 16.

(Heat Exchanger)

The heat exchanger 26 is configured to exchange heat between the circulating gas flowing through the suctioned gas line 22A and the circulating gas flowing through the compressed gas line 22B. The circulating gas flowing through the compressed gas line 22B is compressed by the compressor 24 to become higher in temperature than the circulating gas flowing through the suctioned gas line 22A. As a result of the heat exchange by the heat exchanger 26, the circulating gas flowing through the compressed gas line 22B is cooled with the circulating gas flowing through the suctioned gas line 22A and the circulating gas flowing through the suctioned gas line 22A is heated with the circulating gas flowing through the compressed gas line 22B. In other words, the heat exchanger 26 includes a low-temperature side heat exchange part 261 provided in the suctioned gas line 22A and causing the circulating gas to flow therethrough, and a high-temperature side heat exchange part 262 provided in the compressed gas line 22B and causing the circulating gas to flow therethrough, and is configured to move heat from the circulating gas flowing through the high-temperature side heat exchange part 262 to the circulating gas flowing through the low-temperature side heat exchange part 261.

(Cooler)

As shown in FIGS. 3 and 4, the reefer container 100 may further include a cooler 32 provided between the compressor 24 and the heat exchanger 26 (high-temperature side heat exchange part 262) in the circulation line 22. The cooler 32 is provided upstream from the heat exchanger 26 in the compressed gas line 22B and configured to exchange heat between the circulating gas flowing through the compressed gas line 22B (circulation line 22) and a coolant (for example, water) lower in temperature than this circulating gas. As a result of the heat exchange by the cooler 32, the circulating gas flowing through the compressed gas line 22B toward the heat exchanger 26 is cooled with the coolant. The circulating gas cooled by the cooler 32 is introduced into the heat exchanger 26 (high-temperature side heat exchange part 262) through the compressed gas line 22B.
In the embodiments shown in FIGS. 3 and 4, the reefer container 100 further includes a coolant circulation line 34 for causing the coolant to circulate therethrough. The coolant is supplied to the cooler 32 through the coolant circulation line 34. More specifically, the coolant circulation line 34 is provided with a radiator 38 forming a cooling device 36 for cooling the coolant, and a pump 42 for feeding the coolant along the coolant circulation line 34. The cooling device 36 includes the radiator 38 and a fan 40 for air-cooling the radiator 38. After the coolant is increased in temperature as a result of the heat exchange with the circulating gas flowing through the compressed gas line 22B by the cooler 32, the coolant is fed by the pump 42 to the coolant circulation line 34 and cooled by the cooling device 36 including the radiator 38. The coolant cooled by the cooling device 36 is supplied to the cooler 32 through the coolant circulation line 34. The refrigerant circulating through the coolant circulation line 34 is not limited to a liquid form but may be a gaseous form. The refrigerant circulating through the coolant circulation line 34 may be a fluorine-based refrigerant (refrigerant gas) such as R-1234ZE, for example, or may be an antifreeze liquid such as glycol water, for example. The refrigerant circulating through the coolant circulation line 34 preferably has a lower freezing point than water.

(Compressor, Expander)

In some embodiments, the expander 28 may be coupled to the compressor 24 via a rotational shaft 44. In the embodiments shown in FIGS. 3 and 4, the reefer container 100 further includes an electric motor 46 configured to generate driving force for driving the compressor 24. The compressor 24 includes an electric compressor configured to compress the circulating gas by being driven by the electric motor 46. The compressor 24 and the expander 28 are arranged coaxially with each other via the rotational shaft 44 as an output shaft of the electric motor 46 for driving the compressor 24, and are each connected to the rotational shaft 44. The electric motor 46 is supplied with a current from a power source (such as a generator) not shown in the drawings, and is driven by the current supplied from the power source to drive the rotational shaft 44, the compressor 24, and the expander 28. At the expander 28, part of expansion energy generated during gas expansion is recovered, and the recovered expansion energy is used for assisting in driving of the compressor 24.
As shown in FIG. 4, each of the suctioned gas line 22A, the compressed gas line 22B, and the expanded gas line 22C is formed using pipes. The respective pipes forming the circulation line 22 may be a plurality of pipe sections connected via flanges, etc.
In the embodiment shown in FIG. 4, the pipes forming the suctioned gas line 22A include a pipe 23A provided between the suction port 20 and an inlet of the heat exchanger 26, and a pipe 23B provided between an outlet of the heat exchanger 26 and the compressor 24. The pipes forming the compressed gas line 22B include a pipe 23C provided between an outlet of the compressor 24 and an inlet of the cooler 32, a pipe 23D provided between an outlet of the cooler 32 and the inlet of the heat exchanger 26, and a pipe 23E provided between the outlet of the heat exchanger 26 and an inlet of the expander 28. The pipe forming the expanded gas line 22C includes a pipe 23F provided between an outlet of the expander 28 and the blowout port 16.

(Warmed Gas Introduction Line)

Each of FIGS. 6 to 10 and FIG. 12 is a diagram schematically showing a circuit of the refrigerator 30 of the reefer container 100 according to one embodiment of the present disclosure. FIG. 11 is a view of the reefer container 100 according to one embodiment of the present disclosure (the reefer container 100 shown in FIG. 12) viewed from the direction indicated by the arrow A in FIG. 2.
As shown in FIGS. 3, 4, and 6 to 12, the reefer container 100 according to some embodiments includes the above-described container body 1, the above-described circulation line 22, the above-described compressor 24, the above-described heat exchanger 26, the above-described expander 28, and a warmed gas introduction line 50.
The warmed gas introduction line 50 forms at least a part of a flow path for extracting the circulating gas higher in temperature than the internal gas from between the compressor 24 and the heat exchanger 26 (high-temperature side heat exchange part 262) in the circulation line 22 and guiding the extracted circulating gas to the container body 1. As shown in FIGS. 4 and 9, parts of the warmed gas introduction line 50 are formed using respective pipes. The respective pipes forming the warmed gas introduction line 50 may be a plurality of pipe sections connected via flanges, etc.
The circulating gas flowing between the compressor 24 and the heat exchanger 26 (high-temperature side heat exchange part 262) in the circulation line 22 is compressed by the compressor 24 to be increased in temperature and pressure, thereby becoming the circulating gas higher in temperature and pressure than the internal gas. Guiding the circulating gas thereby brought to higher temperature and pressure than the internal gas into the container body 1 through the warmed gas introduction line 50 allows a temperature inside the container to be increased.
The refrigerator 30 constructed by the above-described configuration includes the compressor 24, the heat exchanger 26, and the expander 28 each provided in the circulation line 22, and uses the gas inside the container body 1 (internal gas) as a heating medium. The gas inside the container body 1 is caused to circulate naturally from the blowout port 16 to the suction port 20 as a result of a difference between a pressure at the blowout port 16 and a pressure at the suction port 20, thereby eliminating a need for a fan for circulation of internal air. This does not cause increase in a temperature inside the container due to provision of a fan and a fan motor inside the container body 1. Thus, a temperature inside the container is easily maintained at an intended temperature. The absence of a fan and a fan motor inside the container body 1 makes it possible to ensure a wide cargo space inside the container body 1. Thus, the above-described configuration provides the reefer container 100 capable of suppressing reduction in a cargo space inside the container and capable of maintaining a temperature inside the container stably.
According to the above-described configuration, the circulating gas brought to a higher temperature than the internal gas by the compressor 24 is returned to the inside of the container body 1 through the warmed gas introduction line 50, thereby allowing a temperature inside the container to be increased. By the provision of the warmed gas introduction line 50 outside the container body 1, the reefer container 100 becomes capable of expanding a range where a temperature inside the container is adjustable to a higher temperature side while suppressing reduction in a cargo space inside the container.

(Warmed Gas Flow Controller)

As shown in FIGS. 3, 4, and 6 to 12, in some embodiments, the above-described reefer container 100 further includes at least one warmed gas flow controller (warmed gas flow control valve) 52 provided in the warmed gas introduction line 50 and configured to allow control of the flow rate of the circulating gas flowing through the warmed gas introduction line 50. The warmed gas flow controller 52 is configured to allow control of the flow rate of the circulating gas to be guided downstream from the warmed gas flow controller 52 (toward a downstream end 502) by changing a degree of opening of a valve element arranged in the warmed gas introduction line 50. The warmed gas flow controller 52 may be an on-off valve controllable in a degree of opening to a fully-closed state and a fully-open state, or may be an opening control valve controllable in a degree of opening to a fully-closed state, a fully-open state, and at least one intermediate degree of opening between the fully-closed state and the fully-opened state.
In the embodiments shown in FIGS. 3, 4, 6 to 8, 11, and 12, by closing the warmed gas flow controller 52 (by reducing a degree of opening of the valve element) while the refrigerator 30 is operating, the circulating gas flowing through the compressed gas line 22B is guided to the expander 28, decreased in temperature through the expansion by the expander 28, and then guided into the container body 1. By opening the warmed gas flow controller 52 (by increasing a degree of opening of the valve element) while the refrigerator 30 is operating, pressure loss at the inlet of the expander 28 becomes larger than that at the warmed gas introduction line 50 or at the warmed gas flow controller 52. Then, as a result of a difference between a pressure at an upstream end 501 and a pressure at the downstream end 502 of the warmed gas introduction line 50, the circulating gas flowing through the compressed gas line 22B is guided into the container body 1 through the warmed gas introduction line 50. This eliminates a need for a fan for guiding the circulating gas into the container body 1 through the warmed gas introduction line 50.
According to the above-described configuration, it is possible to control temperature increase inside the container body 1 by controlling the flow rate of the warmed gas (circulating gas) flowing through the warmed gas introduction line 50 using the warmed gas flow controller 52. In this case, this control of the temperature increase can be exerted simply. Increasing and reducing an output from the electric motor 46 (the number of rotations thereof) increases and reduces the flow rate of the circulating gas to be ejected from the compressor 24 and to flow through the compressed gas line 22B. For this reason, in addition to a degree of opening of the warmed gas flow controller 52, an output from the electric motor 46 (the number of rotations thereof) is preferably used as a parameter for controlling temperature increase inside the container body 1.
In the embodiments shown in FIGS. 9 and 10, the above-described reefer container 100 further includes at least one circulating gas flow controller (circulating gas flow control valve) 29 provided in the circulation line 22 bypassed by the warmed gas introduction line 50 and configured to allow control of the flow rate of the circulating gas flowing through this circulation line 22. Here, the circulation line 22 bypassed by the warmed gas introduction line 50 is a segment of the circulation line 22 between a connection position P1 or P2 to which the upstream end 501 of the warmed gas introduction line 50 is connected and a connection position P4 to which the downstream end 502 of the warmed gas introduction line 50 is connected. In the embodiments shown in FIGS. 9 and 10, the circulating gas flow controller 29 is provided between the heat exchanger 26 (high-temperature side heat exchange part 262) and the connection position P4 in the circulation line 22. Alternatively, the circulating gas flow controller 29 may be provided between the connection position P1 or P2 and the heat exchanger 26 (high-temperature side heat exchange part 262) in the circulation line 22.
The circulating gas flow controller 29 is configured to allow control of the flow rate of the circulating gas to be guided downstream from the circulating gas flow controller 29 (toward the expander 28) by changing a degree of opening of a valve element arranged in the circulation line 22 bypassed by the warmed gas introduction line 50. The circulating gas flow controller 29 may be an on-off valve controllable in a degree of opening to a fully-closed state and a fully-open state, or may be an opening control valve controllable in a degree of opening to a fully-closed state, a fully-open state, and at least one intermediate degree of opening between the fully-closed state and the fully-opened state.
In the embodiments shown in FIGS. 9 and 10, by opening the circulating gas flow controller 29 (by increasing a degree of opening of the valve element) and closing the warmed gas flow controller 52 (by reducing a degree of opening of the valve element) while the refrigerator 30 is operating, the circulating gas flowing through the compressed gas line 22B is guided to the expander 28, decreased in temperature through the expansion by the expander 28, and then guided into the container body 1. By closing the circulating gas flow controller 29 (by reducing a degree of opening of the valve element) and opening the warmed gas flow controller 52 (by increasing a degree of opening of the valve element) while the refrigerator 30 is operating, pressure loss at the circulating gas flow controller 29 provided in the circulation line 22 bypassed by the warmed gas introduction line 50 becomes larger than that at the warmed gas introduction line 50 or at the warmed gas flow controller 52. Then, as a result of a difference between a pressure at the upstream end 501 and a pressure at the downstream end 502 of the warmed gas introduction line 50, the circulating gas flowing through the compressed gas line 22B is guided into the container body 1 through the warmed gas introduction line 50. This eliminates a need for a fan for guiding the circulating gas into the container body 1 through the warmed gas introduction line 50.
According to the above-described configuration, it is possible to control temperature increase inside the container body 1 by controlling the flow rate of the warmed gas (circulating gas) flowing through the warmed gas introduction line 50 using the warmed gas flow controller 52 and the circulating gas flow controller 29. In this case, this control of the temperature increase can be exerted simply.

(Connection Position of Warmed Gas Introduction Line)

As shown in FIGS. 3, 4, 6, 7, 9, 11, and 12, in some embodiments, the upstream end 501 of the warmed gas introduction line 50 described above is connected to the compressed gas line 22B (pipe 23D) at the connection position P1 located between the cooler 32 and the heat exchanger 26 (high-temperature side heat exchange part 262) in the compressed gas line 22B (circulation line 22). In this case, the circulating gas cooled by the cooler 32 is introduced into the warmed gas introduction line 50.
In the illustrated embodiment, the pipes forming the warmed gas introduction line 50 include a pipe 55A provided between the connection position P1 in the pipe 23D (compressed gas line 22B) and an inlet of the warmed gas flow controller 52. The pipe 55A has the above-described upstream end 501.
In one embodiment, the circulating gas increased in pressure by the compressor 24 is brought to a high temperature of equal to or greater than 100°C. The circulating gas cooled by the cooler 32 is brought to an ordinary temperature of equal to or greater than 0°C and equal to or less than 60°C. In this case, the circulating gas at the ordinary temperature and the high pressure is introduced into the container body 1 through the warmed gas introduction line 50.
According to the above-described configuration, the circulating gas brought to a high temperature by the compressor 24 is cooled by the cooler 32, making it possible to reduce a temperature difference between the circulating gas (warmed gas) introduced into the container body 1 through the warmed gas introduction line 50 and the internal gas. Reducing this temperature difference allows the internal gas to be increased gently in temperature using the above-described warmed gas. This makes it possible to suppress damage due to thermal strain inside the container body 1.
As shown in FIGS. 8 and 10, in some embodiments, the upstream end 501 of the warmed gas introduction line 50 described above is connected to the compressed gas line 22B (pipe 23C) at the connection position P2 located between the compressor 24 and the cooler 32 in the compressed gas line 22B (circulation line 22).
In the illustrated embodiment, the pipes forming the warmed gas introduction line 50 include a pipe 55B provided between the connection position P2 in the pipe 23C (compressed gas line 22B) and the inlet of the warmed gas flow controller 52. The pipe 55B has the above-described upstream end 501.
In one embodiment, the circulating gas increased in pressure by the compressor 24 is brought to a high temperature of equal to or greater than 100°C. In this case, the circulating gas at the high temperature and the high pressure not cooled by the cooler 32 is introduced into the container body 1 through the warmed gas introduction line 50.
If the circulating gas having passed through the cooler 32 is introduced as warmed gas into the container body 1, temperature change to be caused by the cooler 32 is required to be considered in exerting temperature increase control inside the container body 1. According to the above-described configuration, the circulating gas brought to a high temperature by the compressor 24 is introduced as warmed gas into the container body 1 without passing through the cooler 32. In this case, temperature change to be caused by the cooler 32 is not required to be considered in exerting temperature increase control inside the container body 1, so that this temperature increase control can be exerted simply.
As shown in FIG. 3, in some embodiments, a blowout port 503 (opening) is formed at the downstream end 502 of the warmed gas introduction line 50 described above for blowing a gas such as air into the container body 1. The above-described suction unit 18 may include the suction port 20 and the blowout port 503. The circulating gas flowing through the warmed gas introduction line 50 is guided to the blowout port 503 and blown from the warmed gas introduction line 50 into the container body 1 through the blowout port 503.
In the illustrated embodiment, the pipes forming the warmed gas introduction line 50 include the above-described pipe 55A, and a pipe 56A provided between an outlet of the warmed gas flow controller 52 and the blowout port 503. The pipe 56A has the above-described downstream end 502. The pipes forming the warmed gas introduction line 50 may include the above-described pipe 55B and the above-described pipe 56A.
As shown in FIGS. 6 to 8, 11, and 12, in some embodiments, the downstream end 502 of the warmed gas introduction line 50 described above is connected to the expanded gas line 22C (pipe 23F) at a connection position P3 located between the expander 28 and the blowout port 16 in the circulation line 22 (expanded gas line 22C). The circulating gas flowing through the warmed gas introduction line 50 is introduced into the container body 1 through a position in the expanded gas line 22C downstream from the connection position P3.
In the illustrated embodiment, the pipes forming the warmed gas introduction line 50 include either one of the pipe 55A and the pipe 55B described above, and a pipe 56B provided between the outlet of the warmed gas flow controller 52 and the connection position P3 in the pipe 23F (expanded gas line 22C). The pipe 56B has the above-described downstream end 502.
According to the above-described configuration, a part of the circulation line 22 such as the blowout port 16 (a part of the expanded gas line 22C between the connection position P3 and the blowout port 16) is available as a flow path for the warmed gas (the circulating gas flowing through the warmed gas introduction line 50). In this case, it is not required to provide the blowout port 503 dedicated to introduction of the warmed gas into the container body 1, making it possible to encourage compactness and weight reduction of the construction of the reefer container 100.
According to the above-described configuration, the circulation line 22 bypassed by the warmed gas introduction line 50 is subjected to large pressure loss by the expander 28 provided in this circulation line 22. This allows a large quantity of the circulating gas to be guided toward the warmed gas introduction line 50 when the warmed gas introduction line 50 is open. This configuration does not require the above-described circulating gas flow controller 29. Furthermore, the circulating gas passing through the warmed gas introduction line 50 is at a higher temperature than the circulating gas passing through the circulation line 22 bypassed by the warmed gas introduction line 50. Thus, the above-described configuration allows a large quantity of the circulating gas at a relatively high temperature to be guided into the container body 1 through the warmed gas introduction line 50, making it possible to provide large heating capacity inside the container body 1.
As shown in FIGS. 9 and 10, in some embodiments, the downstream end 502 of the warmed gas introduction line 50 described above is connected to the compressed gas line 22B at the connection position P4 located between the heat exchanger 26 (high-temperature side heat exchange part 262) and the expander 28 in the compressed gas line 22B (circulation line 22). The circulating gas flowing through the warmed gas introduction line 50 is introduced into the container body 1 through a part of the compressed gas line 22B downstream from the connection position P4, the expander 28, and the expanded gas line 22C.
In the illustrated embodiment, the pipes forming the warmed gas introduction line 50 include either one of the pipe 55A and the pipe 55B described above, and a pipe 56C provided between the outlet of the warmed gas flow controller 52 and the connection position P4 in the compressed gas line 22B. The pipe 56C has the above-described downstream end 502.
According to the above-described configuration, a part of the circulation line 22 such as the blowout port 16 (a part of the circulation line 22 between the connection position P4 and the blowout port 16) is available as a flow path for the warmed gas (the circulating gas flowing through the warmed gas introduction line 50). In this case, it is not required to provide the blowout port 503 dedicated to introduction of the warmed gas into the container body 1, making it possible to encourage compactness and weight reduction of the construction of the reefer container 100.
According to the above-described configuration, the downstream end 502 of the warmed gas introduction line 50 is connected to a position in the circulation line 22 upstream from the expander 28. Thus, compared to a case where the downstream end 502 is connected to a position in the circulation line 22 downstream from the expander 28, it is possible to reduce heat input from the warmed gas introduction line 50 to a part of the circulation line 22 downstream from the expander 28, thereby increasing a gain of cooling performance during refrigerating operation of the reefer container 100.

(Arrangement of Devices Forming Refrigerator)

As shown in FIGS. 1, 4, and 11, in some embodiments, the compressor 24, the cooler 32, the heat exchanger 26, and the expander 28, each provided in the circulation line 22, are arranged in the external space 3 external to the container body 1 and along a partition wall 10 separating the internal space 2 in the container body 1 and the external space 3.
In the illustrated embodiment, the above-described devices provided in the circulation line 22 are arranged along the short-side wall 7 functioning as the partition wall 10. In FIG. 1, some of these devices provided in the circulation line 22 are shown schematically by double-dotted chain lines.
As shown in FIGS. 1, 4, and 11, the above-described reefer container 100 may include a cover 12 provided in such a manner as to enclose the above-described devices in the external space 3 external to the container body 1 from above, below, and sides.
As shown in FIGS. 4 and 5, the pipe 23A between the suction port 20 and the heat exchanger 26 may be provided in such a manner as to pass through a through hole 25 formed at the short-side wall 7 (partition wall 10). Furthermore, the pipe 23F between the expander 28 and the blowout port 16 may be provided in such a manner as to pass through a through hole 27 formed at the short-side wall 7 (partition wall 10).
According to the above-described configuration, each of the compressor 24, the cooler 32, the heat exchanger 26, and the expander 28 is installed in the external space 3 external to the container body 1. Specifically, as these devices are not provided in the internal space 2 in the container body 1, it is possible to ensure a wide cargo space inside the container. Furthermore, according to the above-described configuration, it is not required to provide a heat exchanger such as an evaporator in the internal space 2 in the container body 1. Thus, defrosting operation for defrosting of such a heat exchanger is unnecessary. This allows a temperature inside the container to be maintained easily at an intended temperature. Furthermore, according to the above-described configuration, the devices forming the refrigerator 30 are arranged in a relatively narrow space in the external space 3 external to the container body 1 and along the partition wall 10. As the refrigerator 30 added to the container body 1 is installed in a small area in this way, the reefer container 100 including the refrigerator 30 is favorably available as a container for purposes such as transportation.

(Arrangement of Warmed Gas Introduction Line)

As shown in FIGS. 1, 4, and 11, in some embodiments, the compressor 24, the cooler 32, the heat exchanger 26, and the expander 28, each provided in the circulation line 22, are arranged in the external space 3 external to the container body 1 and along the partition wall 10 separating the internal space 2 in the container body 1 and the external space 3. The circulation line 22 and the warmed gas introduction line 50 are also arranged in the external space 3 and along the partition wall 10.
In a directional view vertical to an external surface 101 of the partition wall 10 facing the external space 3 such as that shown in FIGS. 4 and 11, the above-described warmed gas introduction line 50 is arranged in such a manner as not to intersect a cooled gas line 22D connecting the heat exchanger 26 and the expander 28 in the circulation line 22 to each other.
In the illustrated embodiment, the compressor 24 and the expander 28 are arranged side by side in a horizontal direction. The heat exchanger 26 and the cooled gas line 22D are arranged on an upper side (one side) in a vertical direction with respect to the compressor 24 and the expander 28. The cooler 32 and the warmed gas introduction line 50 are arranged on a lower side (other side) in the vertical direction with respect to the compressor 24 and the expander 28. In other words, the cooler 32 and the warmed gas introduction line 50 are arranged on the opposite side to the heat exchanger 26 and the cooled gas line 22D in the vertical direction across the compressor 24 and the expander 28.
According to the above-described configuration, it is possible to reduce heat input from the circulating gas (warmed gas) flowing through the warmed gas introduction line 50 to the circulating gas (cooled gas) flowing through the cooled gas line 22D, making it possible to encourage performance improvement during refrigerating operation of the reefer container 100.
As shown in FIG. 7, in some embodiments, the above-described reefer container 100 includes the above-described warmed gas introduction line 50 having the upstream end 501 connected between the cooler 32 and the heat exchanger 26 (high-temperature side heat exchange part 262) in the circulation line 22, the above-described electric motor 46, a cooling medium supply line 60, and a cooling medium return line 62. The cooling medium supply line 60 has one end connected to the warmed gas introduction line 50, and forms at least a part of a flow path for extracting the circulating gas from the warmed gas introduction line 50 and supplying the extracted circulating gas to the electric motor 46 as a cooling medium for cooling the electric motor 46. The cooling medium return line 62 forms at least a part of a flow path for returning the circulating gas to a position in the circulation line 22 upstream from the compressor 24 after the circulating gas is supplied to the electric motor 46 through the cooling medium supply line 60.
In the illustrated embodiment, an upstream end (one end) of the cooling medium supply line 60 is connected to a position in the warmed gas introduction line 50 upstream from the warmed gas flow controller 52 (closer to the upstream end 501). A downstream end (one end) of the cooling medium return line 62 is connected between the low-temperature side heat exchange part 261 (heat exchanger 26) and the compressor 24 in the circulation line 22. The upstream end (one end) of the cooling medium supply line 60 may be connected between the cooler 32 and the heat exchanger 26 (high-temperature side heat exchange part 262) in the circulation line 22.
The reefer container 100 may include a motor cooler 64. The motor cooler 64 receives the circulating gas cooled by the cooler 32 and guided through the cooling medium supply line 60. The motor cooler 64 is configured to exchange heat between the electric motor 46 and the circulating gas at a lower temperature than the electric motor 46 guided to the motor cooler 64. As a result of the heat exchange by the motor cooler 64, the electric motor 46 is cooled with the circulating gas guided to the motor cooler 64. The circulating gas having been used in the motor cooler 64 for cooling the electric motor 46 is returned through the cooling medium return line 62 to a position in the circulation line 22 upstream from the compressor 24.
According to the above-described configuration, by the provision of the cooling medium supply line 60 and the cooling medium return line 62, the reefer container 100 becomes capable of cooling the electric motor 46 with the circulating gas extracted from the warmed gas introduction line 50 and returning the circulating gas having been used for cooling the electric motor 46 to the circulation line 22. In this case, the circulation line 22, the warmed gas introduction line 50 and the like are available in part as a flow path for the cooling medium (circulating gas) for cooling the electric motor 46, making it possible to encourage compactness and weight reduction of the configuration of the reefer container 100.

(First Warmed Gas Flow Controller, Second Warmed Gas Flow Controller)

FIG. 13 is a schematic sectional view of the warmed gas flow controller 52 (53, 54) of the reefer container according to one embodiment of the present disclosure.
As shown in FIGS. 11 to 13, in some embodiments, the at least one warmed gas flow controller (warmed gas flow control valve) 52 described above includes a first warmed gas flow controller (warmed gas flow control valve) 53 provided in the warmed gas introduction line 50, and a second warmed gas flow controller (warmed gas flow control valve) 54 provided downstream from the first warmed gas flow controller 53 (closer to the downstream end 502) in the warmed gas introduction line 50. The first warmed gas flow controller 53 and the second warmed gas flow controller 54 are also applicable to the above-described embodiments shown in FIGS. 1 to 10.
The first warmed gas flow controller 53 and the second warmed gas flow controller 54 are configured to allow control of the flow rate of the circulating gas to be guided downstream from the warmed gas flow controller 52 (53, 54) (toward the downstream end 502) by changing degrees of opening of valve elements 531 and 541 respectively arranged in the warmed gas introduction line 50. Each of the first warmed gas flow controller 53 and the second warmed gas flow controller 54 may be an on-off valve controllable in a degree of opening to a fully-closed state and a fully-open state, or may be an opening control valve controllable in a degree of opening to a fully-closed state, a fully-open state, and at least one intermediate degree of opening between the fully-closed state and the fully-opened state.
According to the above-described configuration, providing the two warmed gas flow controllers 53 and 54 in the warmed gas introduction line 50 makes it possible to improve heat shielding performance in the warmed gas introduction line 50. As a result, it is possible to reduce heat input to a part of the warmed gas introduction line 50 downstream from the second warmed gas flow controller 54 when the two warmed gas flow controllers 53 and 54 are closed.
In the embodiment shown in FIG. 13, the first warmed gas flow controller 53 and the second warmed gas flow controller 54 have flange parts 532 and 542 respectively. With a packing 521 as a heat insulator interposed between the flange part 542 and the flange part 532, the flange part 542 is fastened to the flange part 532 via a fastening member (in the illustrated example, a bolt and a nut) 522. Providing the packing 521 between the two warmed gas flow controllers 53 and 54 achieves improvement of heat shielding performance in the warmed gas introduction line 50. This makes it possible to reduce heat input to a part of the warmed gas introduction line 50 downstream from the second warmed gas flow controller 54 when the two warmed gas flow controllers 53 and 54 are closed.
Each of FIGS. 14 and 15 is a diagram schematically showing a circuit of the refrigerator 30 of the reefer container 100 according to one embodiment of the present disclosure. FIG. 16 is a schematic view of a deodorizing device 70 of the reefer container 100 according to one embodiment of the present disclosure.
As shown in FIGS. 14 and 15, in some embodiments, the above-described reefer container 100 further includes the deodorizing device 70 configured to emit a substance having a deodorizing function to the circulating gas. This is also applicable to the above-described embodiments shown in FIGS. 1 to 13.
The deodorizing device 70 is preferably configured to generate the substance having a deodorizing function from the circulating gas. In the embodiment shown in FIG. 16, the internal gas and the circulating gas contain air, and the deodorizing device 70 includes an ozone generator 70A configured to generate ozone from the air in the circulating gas. The ozone generator 70A includes electrodes 71, 72 in a pair arranged in a state of facing each other, and a dielectric 73 arranged between the electrodes 71, 72 in a pair. The air in the circulating gas is introduced between the electrodes 71, 72 in a pair, a discharge phenomenon is generated when an alternating high voltage is applied between the electrodes 71, 72 in a pair from an applicator not shown in the drawings, and oxygen in the air is converted to ozone by electrons generated as a result of the discharge phenomenon. The ozone generator 70A may be configured to generate ozone by emitting radiation to the air in the circulating gas.
The deodorizing device 70 may be configured to generate a substance originating from moisture and having a deodorizing function by applying a high voltage or emitting an ultrasonic wave, for example, to at least one of moisture in the circulating gas and water stored in the deodorizing device 70. The substance originating from moisture and having a deodorizing function may be a charged microparticle.
The deodorizing device 70 is configured to degerm and deodorize the circulating gas by emitting ozone or the substance originating from moisture and having a deodorizing function to the circulating gas. The circulating gas (air) flowing through the above-described circulation line 22 or warmed gas introduction line 50 is dry. Thus, it is easy to generate the substance having a deodorizing function to achieve high deodorizing effect using the substance having a deodorizing function.
According to the above-described configuration, it is possible to deodorize the circulating gas by causing the deodorizing device 70 to emit the substance having a deodorizing function to the circulating gas. It is also possible to deodorize the internal gas by returning the circulating gas deodorized by the deodorizing device 70 into the container body 1. In this case, the deodorizing device 70 can be provided outside the container body 1 unlike in a case where the internal gas is to be deodorized directly by the deodorizing device 70, making it possible to ensure a wide cargo space inside the container body 1. In providing the deodorizing device 70 outside the container body 1, the deodorizing device 70 is preferably provided in a line such as the circulation line 22 or the warmed gas introduction line 50 through which the gas (circulating gas) extracted from inside the container body 1 is to flow. In this case, a line such as the circulation line 22 or the warmed gas introduction line 50 is available as a flow path for a fluid between the container body 1 and the deodorizing device 70, making it possible to encourage compactness and weight reduction of the construction of the reefer container 100.
As shown in FIG. 14, in some embodiments, the above-described deodorizing device 70 is provided in the warmed gas introduction line 50. In the embodiment shown in FIG. 14, the deodorizing device 70 is installed upstream from the warmed gas flow controller 52 (closer to the upstream end 501) in the warmed gas introduction line 50.
According to the above-described configuration, providing the deodorizing device 70 in the warmed gas introduction line 50 makes it possible to reduce a likelihood that the substance having a deodorizing function will be guided to the expander 28 in a low-temperature environment. Thus, it is possible to reduce a likelihood that the substance having a deodorizing function will be less effective or will be frozen in the expander 28. As a result, even if the quantity of the substance having a deodorizing function to be emitted from the deodorizing device 70 is reduced, deodorizing effect is still achieved actively. Furthermore, by providing the deodorizing device 70 in the warmed gas introduction line 50, the substance having a deodorizing function is guided into the container body 1. This allows the internal gas to be degermed and deodorized directly with the substance having a deodorizing function.
As shown in FIG. 15, in some embodiments, the above-described deodorizing device 70 is installed in ordinary-temperature environment areas in the circulation line 22 through which the circulating gas at an ordinary temperature (equal to or greater than 0°C and equal to or less than 60°C) flows. In the embodiment shown in FIG. 15, the above-described deodorizing device 70 may be installed between the cooler 32 and the heat exchanger 26 (high-temperature side heat exchange part 262) in the circulation line 22, which is one of these ordinary-temperature environment areas. The above-described deodorizing device 70 may be installed between the low-temperature side heat exchange part 261 (heat exchanger 26) and the compressor 24 in the circulation line 22, which is one of these ordinary-temperature environment areas.
According to the above-described configuration, providing the deodorizing device 70 in the above-described ordinary-temperature environment area in the circulation line 22 makes it possible to reduce a likelihood that the substance having a deodorizing function will be guided to the expander 28 in a low-temperature environment. Thus, it is possible to reduce a likelihood that the substance having a deodorizing function will be less effective or will be frozen in the expander 28. As a result, even if the quantity of the substance having a deodorizing function to be emitted from the deodorizing device 70 is reduced, deodorizing effect is still achieved actively. In particular, a pressure is relatively low between the low-temperature side heat exchange part 261 (heat exchanger 26) and the compressor 24 in the circulation line 22, so that the substance having a deodorizing function is emitted easily to the circulating gas. Furthermore, even in the reefer container 100 where the internal gas is cooled to an ultra low temperature of equal to or less than -40°C, the circulating gas still flows as ordinary-temperature dry air between the low-temperature side heat exchange part 261 (heat exchanger 26) and the compressor 24 in the circulation line 22. Thus, it is easy to generate the substance having a deodorizing function to achieve high deodorizing effect using the substance having a deodorizing function.
In some embodiments, at least one of the above-described heat exchanger 26 and cooler 32 may include a plate heat exchanger or a microchannel heat exchanger. The plate heat exchanger or the microchannel heat exchanger may be formed using a material containing aluminum or titanium.
In some embodiments, the suction port 20 is provided with a filter part 21 such as that shown in FIG. 5 for removing a foreign matter. The filter part 21 includes a member with a plurality of holes or meshes, etc., and has a plurality of openings defined by these holes or meshes, for example.
As shown in FIG. 1, in some embodiments, the partition wall 10 (in the example shown in FIG. 1, the short-side wall 7 of the container body 1), making a separation between a region where the compressor 24, the cooler 32, the heat exchanger 26, and the expander 28 are installed externally to the container body 1 and the internal space 2 in 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 26, expander 28) forming the refrigerator 30 are arranged in a relatively narrow space along the partition wall 10 (short-side wall 7) that is a relatively small wall extending along the plane perpendicular to the longitudinal direction of the container body 1. This allows reduction in an installation area for the refrigerator 30 to be added to the container body 1, thereby making the reefer container 100 including the refrigerator 30 favorably available as a container for purposes such as transportation.
In one embodiment, the compressor 24, the cooler 32, the heat exchanger 26, and expander 28 arranged in the external space 3 may be located within a range where a length L1 from the partition wall 10 in the longitudinal direction of the container body 1 is equal to or less than 1/10 of a length L0 of the container body 1 (see FIG. 1).
In this case, an installation area for the devices forming the refrigerator 30 is within the range of equal to or less than 1/10 of the length L0 of the container body 1. This results in a small installation area for the refrigerator 30 to be added to the container body 1, thereby making the reefer container 100 including the refrigerator 30 favorably available as a container for purposes such as transportation.
If the container body 1 is a 20-ft container (length L0: approximately 6.1 m, width WO: approximately 2.4 m, height H0: approximately 2.6 m), for example, the length (L1) of the above-described installation area may be equal to or less than 610 mm.
In the present description, an expression indicating relative or absolute arrangement such as "in one direction," "along one direction," "parallel," "perpendicular," "center," "concentric," or "coaxial" shall not be construed as indicating only such arrangement in a strict sense, but shall also be construed as including a state where the arrangement is relatively displaced by a tolerance, or by such an angle or such a distance as will provide the same function.
As an example, an expression indicating an equal state between matters such as "same," "equal," or "uniform" shall not be construed as indicating only a state where the matters are strictly equal, but shall also be construed as including a state in the presence of a tolerance or such a difference as will provide the same function.
In the present description, an expression indicating a shape such as a rectangular shape or a cylindrical shape shall not be construed as indicating only a rectangular shape or a cylindrical shape in a geometrically strict sense, but shall also be construed as including a shape with projections and recesses or chamfered corners within a range where it is possible to provide the same function.
In the present description, an expression "comprising," "including," or "having" one constitutional element is not an exclusive expression excluding the presence of other constitutional elements.
The present disclosure is not limited to the above-described embodiments but also includes embodiments obtained by modifying the above-described embodiments or embodiments obtained by combining these embodiments together as appropriate.
The contents described in some of the embodiments described above will be understood as follows, for example.

1) A reefer container (100) according to at least one embodiment of the present disclosure is a reefer container (100) configured to allow cooling of an internal gas corresponding to a gas inside a container body (1), comprising:
- the container body (1);
- a circulation line (22) having a suction port (20) and a blowout port (16) each provided inside the container body (1);
- a compressor (24) provided in the circulation line (22) and configured to compress a circulating gas corresponding to the gas suctioned into the circulation line (22) from inside the container body (1) through the suction port (20);
- a heat exchanger (26) provided in the circulation line (22) and configured to cool the circulating gas compressed by the compressor (24);
- an expander (28) provided in the circulation line (22) and configured to expand the circulating gas cooled by the heat exchanger (26); and
- a warmed gas introduction line (50) for extracting the circulating gas higher in temperature than the internal gas from between the compressor (24) and the heat exchanger (26) in the circulation line (22) and guiding the extracted circulating gas to the container body (1).

A refrigerator (30) constructed by the configuration described in the above 1) includes the compressor (24), the heat exchanger (26), and the expander (28) each provided in the circulation line (22), and uses the gas inside the container body (1) (internal gas) as a heating medium. The gas inside the container body (1) is caused to circulate naturally from the blowout port (16) to the suction port (20) as a result of a difference between a pressure at the blowout port (16) and a pressure at the suction port (20), thereby eliminating a need for a fan for circulation of the circulating gas. This does not cause increase in a temperature inside the container due to provision of a fan and a fan motor inside the container body (1). Thus, a temperature inside the container is easily maintained at an intended temperature. The absence of a fan and a fan motor inside the container body (1) makes it possible to ensure a wide cargo space inside the container body (1). Thus, the configuration described in the above 1) provides the reefer container (100) capable of suppressing reduction in a cargo space inside the container and capable of maintaining a temperature inside the container stably.
According to the configuration described in the above 1), the circulating gas brought to a higher temperature than the internal gas by the compressor (24) is returned to the inside of the container body (1) through the warmed gas introduction line (50), thereby allowing a temperature inside the container to be increased. By the provision of the warmed gas introduction line (50) outside the container body (1), the reefer container (100) becomes capable of expanding a range where a temperature inside the container is adjustable to a higher temperature side while suppressing reduction in a cargo space inside the container.
2) In some embodiments, in the reefer container (100) described in the above 1), the reefer container (100) further comprises:

a cooler (32) provided downstream from the compressor (24) and upstream from the heat exchanger (24) in the circulation line (22) and configured to exchange heat between the circulating gas and a coolant, wherein
an upstream end (501) of the warmed gas introduction line (50) is connected between the cooler (32) and the heat exchanger (26) in the circulation line (22).

According to the configuration described in the above 2), the circulating gas brought to a high temperature by the compressor (24) is cooled by the cooler (32), making it possible to reduce a temperature difference between the circulating gas (warmed gas) introduced into the container body (1) through the warmed gas introduction line (50) and the internal gas. Reducing this temperature difference allows the internal gas to be increased gently in temperature using the above-described warmed gas. This makes it possible to suppress damage due to thermal strain inside the container body (1).
3) In some embodiments, in the reefer container (100) described in the above 1), the reefer container (100) further comprises:

a cooler (32) provided downstream from the compressor (24) and upstream from the heat exchanger (24) in the circulation line (22) and configured to exchange heat between the circulating gas and a coolant, wherein
an upstream end (501) of the warmed gas introduction line (50) is connected between the cooler (32) and the compressor (24) in the circulation line (22).

If the circulating gas having passed through the cooler (32) is introduced as warmed gas into the container body (1), temperature change to be caused by the cooler (32) is required to be considered in exerting temperature increase control inside the container body (1). According to the configuration described in the above 3), the circulating gas brought to a high temperature by the compressor (24) is introduced as warmed gas into the container body (1) without passing through the cooler (32). In this case, temperature change to be caused by the cooler (32) is not required to be considered in exerting temperature increase control inside the container body (1), so that this temperature increase control can be exerted simply.
4) In some embodiments, the reefer container (100) described in any one of the above 1) to the above 3) further comprises:
at least one warmed gas flow controller (52) provided in the warmed gas introduction line (50) and configured to allow control of the flow rate of the gas flowing through the warmed gas introduction line (50).
According to the configuration described in the above 4), it is possible to control temperature increase inside the container body (1) by controlling the flow rate of the warmed gas (circulating gas) flowing through the warmed gas introduction line (50) using the warmed gas flow controller (52). In this case, this control of the temperature increase can be exerted simply.
5) In some embodiments, in the reefer container (100) described in the above 4), the at least one warmed gas flow controller (52) includes:

a first warmed gas flow controller (53) provided in the warmed gas introduction line (50); and
a second warmed gas flow controller (54) provided downstream from the first warmed gas flow controller (53) in the warmed gas introduction line (50).

According to the configuration described in the above 5), providing the two warmed gas flow controllers (53, 54) in the warmed gas introduction line (50) makes it possible to improve heat shielding performance in the warmed gas introduction line (50). As a result, it is possible to reduce heat input to a part of the warmed gas introduction line (50) downstream from the second warmed gas flow controller (54) when the two warmed gas flow controllers (53, 54) are closed.
6) In some embodiments, in the reefer container (100) described in any one of the above 1) to the above 5),
a downstream end (502) of the warmed gas introduction line (50) is connected between the expander (28) and the blowout port (16) in the circulation line (22).
According to the configuration described in the above 6), a part of the circulation line (22) such as the blowout port (16) is available as a flow path for the warmed gas (the circulating gas flowing through the warmed gas introduction line 50). In this case, it is not required to provide a blowout port dedicated to introduction of the warmed gas into the container body (1), making it possible to encourage compactness and weight reduction of the construction of the reefer container (100).
According to the configuration described in the above 6), the circulation line (22) bypassed by the warmed gas introduction line (50) is subjected to large pressure loss by the expander (28) provided in this circulation line (22). This allows a large quantity of the circulating gas to be guided toward the warmed gas introduction line (50) when the warmed gas introduction line (50) is open. Furthermore, the circulating gas passing through the warmed gas introduction line (50) is at a higher temperature than the circulating gas passing through the circulation line (22) bypassed by the warmed gas introduction line (50). Thus, the configuration described in the above 6) allows a large quantity of the circulating gas at a relatively high temperature to be guided into the container body (1) through the warmed gas introduction line (50), making it possible to provide large heating capacity inside the container body (1).
7) In some embodiments, in the reefer container (100) described in any one of the above 1) to the above 5),
a downstream end (502) of the warmed gas introduction line (50) is connected between the heat exchanger (24) and the expander (28) in the circulation line (22).
According to the configuration described in the above 7), a part of the circulation line (22) such as the blowout port (16) is available as a flow path for the warmed gas (the circulating gas flowing through the warmed gas introduction line 50). In this case, it is not required to provide a blowout port dedicated to introduction of the warmed gas into the container body (1), making it possible to encourage compactness and weight reduction of the construction of the reefer container (100).
According to the configuration described in the above 7), the downstream end of the warmed gas introduction line (50) is connected to a position in the circulation line (22) upstream from the expander (28). Thus, compared to a case where the downstream end is connected to a position in the circulation line (22) downstream from the expander (28), it is possible to reduce heat input from the warmed gas introduction line (50) to a part of the circulation line (22) downstream from the expander (28), thereby increasing a gain of cooling performance during refrigerating operation of the reefer container (100).
8) In some embodiments, in the reefer container (100) described in any one of the above 1) to the above 7),

the circulation line (22) and the warmed gas introduction line (50) are arranged in an external space (3) external to the container body (1) and along a partition wall (10) separating an internal space (2) in the container body (1) and the external space (3), and
in a directional view vertical to an external surface (101) of the partition wall (10) facing the external space (3), the warmed gas introduction line (50) is arranged in such a manner as not to intersect a cooled gas line (22D) connecting the heat exchanger (26) and the expander (28) in the circulation line (22) to each other.

According to the configuration described in the above 7), it is possible to reduce heat input from the circulating gas (warmed gas) flowing through the warmed gas introduction line (50) to the circulating gas (cooled gas) flowing through the cooled gas line (22D), making it possible to encourage performance improvement during refrigerating operation of the reefer container (100).
9) In some embodiments, the reefer container (100) described in the above 2) further comprises:

an electric motor (46) configured to generate driving force for driving the compressor (24);
a cooling medium supply line (60) having one end connected to the warmed gas introduction line (50), and used for extracting the circulating gas from the warmed gas introduction line (50) and supplying the extracted circulating gas to the electric motor (46) as a cooling medium for cooling the electric motor (46); and
a cooling medium return line (62) for returning the circulating gas to a position in the circulation line (22) upstream from the compressor (24) after the circulating gas is supplied to the electric motor (46) through the cooling medium supply line (60).

According to the configuration described in the above 9), by the provision of the cooling medium supply line (60) and the cooling medium return line (62), the reefer container (100) becomes capable of cooling the electric motor with the circulating gas extracted from the warmed gas introduction line and returning the circulating gas having been used for cooling the electric motor to the circulation line. In this case, the circulation line (22), the warmed gas introduction line (50) and the like are available in part as a flow path for the cooling medium (circulating gas) for cooling the electric motor, making it possible to encourage compactness and weight reduction of the construction of the reefer container (100).
10) In some embodiments, the reefer container (100) described in any one of the above 1) to the above 9) further comprises:
a deodorizing device (70) configured to emit a substance having a deodorizing function to the circulating gas.
According to the configuration described in the above 10), it is possible to deodorize the circulating gas by causing the deodorizing device (70) to emit the substance having a deodorizing function to the circulating gas. It is also possible to deodorize the internal gas by returning the circulating gas deodorized by the deodorizing device (70) into the container body (1). In this case, the deodorizing device (70) can be provided outside the container body (1) unlike in a case where the internal gas is to be deodorized directly by the deodorizing device (70), making it possible to ensure a wide cargo space inside the container body (1). In providing the deodorizing device (70) outside the container body (1), the deodorizing device (70) is preferably provided in a line such as the circulation line (22) or the warmed gas introduction line (50) through which the gas (circulating gas) extracted from inside the container body (1) is to flow. In this case, a line such as the circulation line (22) or the warmed gas introduction line (50) is available as a flow path for the gas between the container body (1) and the deodorizing device (70), making it possible to encourage compactness and weight reduction of the construction of the reefer container (100).
11) In some embodiments, in the reefer container (100) described in the above 10),
the deodorizing device (70) is provided in the warmed gas introduction line (50).
According to the configuration described in the above 11), providing the deodorizing device (70) in the warmed gas introduction line (50) makes it possible to reduce a likelihood that the substance having a deodorizing function will be guided to the expander (28) in a low-temperature environment. Thus, it is possible to reduce a likelihood that the substance having a deodorizing function will be less effective or will be frozen in the expander (28). As a result, even if the quantity of the substance having a deodorizing function to be emitted from the deodorizing device (70) is reduced, active deodorizing effect is still achieved. Furthermore, by providing the deodorizing device (70) in the warmed gas introduction line (50), the substance having a deodorizing function is guided into the container body (1). This allows the internal gas to be degermed and deodorized directly with the substance having a deodorizing function.

Reference Signs List

1: Container body
2: Internal space
3: External space
4: Ceiling wall
5: Bottom ball
6, 7: Short-side wall
8, 9: Long-side wall
10: Partition wall
12: Cover
14: Blowout unit
16: Blowout port
18: Suction unit
20: Suction port
21: Filter part
22: Circulation line
22A: Suctioned gas line
22B: Compressed gas line
22C: Expanded gas line
23A to 23H: Pipe
24: Compressor
25, 27: Through hole
26: Heat exchanger
28: Expander
29: Circulating gas flow controller
30: Refrigerator
32: Cooler
34: Coolant circulation line
36: Cooling device
38: Radiator
40: Fan
42: Pump
44: Rotational shaft
46: Electric motor
50: Warmed gas introduction line
52: Warmed gas flow controller
53: First warmed gas flow controller
54: Second warmed gas flow controller
60: Cooling medium supply line
62: Cooling medium return line
70: Deodorizing device
100: Reefer container

Claims

A reefer container configured to allow cooling of an internal gas corresponding to a gas inside a container body, comprising:
the container body;

a circulation line having a suction port and a blowout port each provided inside the container body;

a compressor provided in the circulation line and configured to compress a circulating gas corresponding to the gas suctioned into the circulation line from inside the container body through the suction port;

a heat exchanger provided in the circulation line and configured to cool the circulating gas compressed by the compressor;

an expander provided in the circulation line and configured to expand the circulating gas cooled by the heat exchanger; and

a warmed gas introduction line for extracting the circulating gas higher in temperature than the internal gas from between the compressor and the heat exchanger in the circulation line and guiding the extracted circulating gas to the container body.
The reefer container according to claim 1, further comprising:
a cooler provided downstream from the compressor and upstream from the heat exchanger in the circulation line and configured to exchange heat between the circulating gas and a coolant, wherein

an upstream end of the warmed gas introduction line is connected between the cooler and the heat exchanger in the circulation line.
The reefer container according to claim 1, further comprising:
a cooler provided downstream from the compressor and upstream from the heat exchanger in the circulation line and configured to exchange heat between the circulating gas and a coolant, wherein

an upstream end of the warmed gas introduction line is connected between the cooler and the compressor in the circulation line.
The reefer container according to any one of claims 1 to 3, further comprising:
at least one warmed gas flow controller provided in the warmed gas introduction line and configured to allow control of the flow rate of the gas flowing through the warmed gas introduction line.
The reefer container according to claim 4, wherein
the at least one warmed gas flow controller includes:
a first warmed gas flow controller provided in the warmed gas introduction line; and

a second warmed gas flow controller provided downstream from the first warmed gas flow controller in the warmed gas introduction line.
The reefer container according to any one of claims 1 to 3, wherein
a downstream end of the warmed gas introduction line is connected between the expander and the blowout port in the circulation line.
The reefer container according to any one of claims 1 to 3, wherein
a downstream end of the warmed gas introduction line is connected between the heat exchanger and the expander in the circulation line.
The reefer container according to any one of claims 1 to 3, wherein
the circulation line and the warmed gas introduction line are arranged in an external space external to the container body and along a partition wall separating an internal space in the container body and the external space, and

in a directional view vertical to an external surface of the partition wall facing the external space, the warmed gas introduction line is arranged in such a manner as not to intersect a cooled gas line connecting the heat exchanger and the expander in the circulation line to each other.
The reefer container according to claim 2, further comprising:
an electric motor configured to generate driving force for driving the compressor;

a cooling medium supply line having one end connected to the warmed gas introduction line, and used for extracting the circulating gas from the warmed gas introduction line and supplying the extracted circulating gas to the electric motor as a cooling medium for cooling the electric motor; and

a cooling medium return line for returning the circulating gas to a position in the circulation line upstream from the compressor after the circulating gas is supplied to the electric motor through the cooling medium supply line.
The reefer container according to any one of claims 1 to 3, further comprising:
a deodorizing device configured to emit a substance having a deodorizing function to the circulating gas.
The reefer container according to claim 10, wherein
the deodorizing device is provided in the warmed gas introduction line.