JP2019152421A - Inside air conditioning device - Google Patents

Abstract

To shorten, in an inside air conditioning device for adjusting a composition of air inside a storage (1) such as a container, a time to return air inside the storage (1), maintained at a low-oxygen concentration to an equivalent to the atmosphere.SOLUTION: A controller (110) is provided with an oxygen concentration recovery control part (111) for performing oxygen concentration recovery operation of supplying high-oxygen concentration gas generated in first and second composition adjusting parts (40,60) capable of generating low-oxygen concentration gas of a lower oxygen concentration than the atmosphere, and high-oxygen concentration gas of a higher oxygen concentration than the atmosphere, to an inside space of a storage (1), and returning an oxygen concentration in the inside space to a target concentration equivalent to the atmosphere.SELECTED DRAWING: Figure 3

Description

  The present disclosure relates to an internal air conditioner that adjusts the composition of internal air in a storage.

  Conventionally, for the purpose of suppressing the decline in freshness of plants such as agricultural products, the interior of the warehouse that adjusts the composition of the warehouse air for storing agricultural products, etc. (for example, the oxygen concentration or carbon dioxide concentration of the air in the warehouse) Air conditioning devices are known.

  Patent Document 1 discloses a container having a device for adjusting the composition of the air in the cabinet. The apparatus of Patent Document 1 adjusts the composition of the internal air using a gas separation membrane that has higher carbon dioxide permeability than oxygen permeability. Specifically, in this apparatus, the air in the cabinet containing carbon dioxide is brought into contact with one surface of the gas separation membrane, and the outside air containing almost no carbon dioxide is brought into contact with the other surface of the gas separation membrane. The carbon dioxide generated by the respiration is discharged to the outside of the container (see the specification, page 20, line 14 to page 21, line 2 of Patent Document 1).

  In a container having this type of equipment, in order to keep the freshness of plants such as agricultural products over a long period of time, generally, the air in the warehouse has an oxygen concentration (for example, 5 to 8%) lower than the oxygen concentration (about 21%) in the atmosphere. Maintained. Also, when taking out cargo such as agricultural products that have been transported or stored in containers, before opening the container door, ventilate and return the oxygen concentration of the air in the cabinet to the atmosphere equivalent, leaving the oxygen concentration low. Processing that does not open the chamber is performed.

International Publication No. 2007/033668

  However, even if the atmosphere with an oxygen concentration of about 21% is introduced by ventilating the interior space of the container where the oxygen concentration is low, the oxygen concentration of the air inside the chamber is immediately about 21% equivalent to the atmosphere. It takes a long time that almost all of the air in the cabinet is replaced with the atmosphere.

  The present disclosure has been made in view of such problems, and an object thereof is to shorten the time for returning the air in the storage of a storage container such as a container maintained at a low oxygen concentration to the atmosphere equivalent. .

  The first aspect of the present disclosure is premised on an internal air conditioner that adjusts the composition of the internal air inside the storage (1).

  The internal air conditioner includes a gas composition control unit (40, 60) capable of generating a low oxygen concentration gas having a lower oxygen concentration than the atmosphere and a high oxygen concentration gas having a higher oxygen concentration than the atmosphere, and the gas Gas passages (53 to 55, 73 to 75, 120) communicating with the composition adjusting unit (40, 60) and the internal space and the external space of the storage (1), and the gas composition adjusting unit (40, 60) The generated low oxygen oxygen gas is supplied to the internal space through the gas passage (53, 55, 73, 75, 120) and the high oxygen concentration gas is supplied to the external through the gas passage (54, 55, 74, 75). And a controller (110) that performs an oxygen concentration reduction operation for discharging to the space and reducing the oxygen concentration of the internal space, and the controller (110) is generated by the gas composition adjustment unit (40, 60). Oxygen supplied to the internal space and the oxygen concentration in the internal space is returned to a concentration corresponding to the atmosphere. Characterized in that it comprises an oxygen concentration recovery control unit which performs time recovery operation the (111).

  In this first aspect, for example, when the oxygen concentration recovery operation is performed before opening the door of the storage (1) such as a container, a high oxygen concentration gas having a higher oxygen concentration than the atmosphere is transferred to the internal space having a lower oxygen concentration. Supplied. Therefore, the rate of increase of the oxygen concentration in the internal space becomes faster than when only the ventilation is performed and the atmosphere is introduced into the internal space.

The second aspect includes a ventilation passage (100) communicating with the internal space and the external space of the storage (1) in the first aspect, and the controller (110) performs the oxygen concentration recovery operation. In some cases, the internal space is ventilated simultaneously by the ventilation passage (100).

  In the second aspect, for example, when the oxygen concentration recovery operation is performed before the storage door (1) such as a container is opened, a high oxygen concentration gas having a higher oxygen concentration than the atmosphere is transferred to the internal space having a lower oxygen concentration. At the same time, ventilation is performed and air is also introduced into the interior space.

  A third aspect is the first or second aspect, wherein the gas composition adjustment unit (40, 60) separates nitrogen and oxygen from the outside air of the storage (1), so that the nitrogen is more than the atmosphere. A first composition control unit (40) that generates a low oxygen concentration gas having a high concentration and a low oxygen concentration and a high oxygen concentration gas having a lower nitrogen concentration and a higher oxygen concentration than the atmosphere by a gas separation membrane (85). The controller (110) supplies the high oxygen concentration gas generated by the first composition adjustment unit (40) to the internal space when performing the oxygen concentration recovery operation.

  In this third aspect, the oxygen concentration is recovered by the first composition adjustment unit (40) that separates nitrogen and oxygen from the outside air of the storage (1) to generate a low oxygen concentration gas and a high oxygen concentration gas. During operation, high oxygen concentration gas is supplied to the interior space of the storage (1).

  According to a fourth aspect, in the third aspect, the gas composition adjustment unit (40, 60) separates nitrogen, oxygen, and carbon dioxide from the internal air of the storage (1), and from the internal air. A gas separation membrane (85) has a low oxygen concentration gas having a high nitrogen concentration and a low oxygen concentration and a low carbon dioxide concentration, and a high oxygen concentration gas having a lower nitrogen concentration and a higher oxygen concentration and a high carbon dioxide concentration than the air in the cabinet. And a second oxygen concentration gas generated by the second composition adjustment unit (60) when the controller (110) performs the oxygen concentration recovery operation. Is supplied to the internal space.

  In this 4th aspect, the 1st composition adjustment part (40) which isolate | separates nitrogen and oxygen from the external air of storage (1), and produces | generates low oxygen concentration gas and high oxygen concentration gas, and storage ( In combination with the second composition control unit (60) that separates nitrogen, oxygen, and carbon dioxide from the air in 1) to produce a low oxygen concentration gas and a high oxygen concentration gas. Oxygen-concentrated gas is supplied to the internal space of the storage (1).

  In the fourth aspect, instead of the first composition adjustment unit (40), nitrogen, oxygen, and carbon dioxide are separated from the internal air of the storage (1) in the fourth aspect, and from the internal air An adsorbent capable of separating a low oxygen concentration gas having a high nitrogen concentration and a low oxygen concentration and a low carbon dioxide concentration and a high oxygen concentration gas having a lower nitrogen concentration and a high oxygen concentration and a high carbon dioxide concentration than the air in the cabinet. The controller (110) includes the adsorbing unit (234, 235) provided, and the controller (110) supplies the high oxygen concentration gas generated by the second composition adjusting unit (60) to the internal space when performing the oxygen concentration recovery operation. It is characterized by supplying.

  In the fifth aspect, the first composition adjusting unit (the low oxygen concentration gas and the high oxygen concentration gas are generated by separating nitrogen and oxygen from the air in the storage (1) by the gas separation membrane (85)). In the configuration including the adsorbing portion (234, 235) provided with the adsorbent in addition to 40), the oxygen concentration recovery operation is performed using the second composition adjusting portion (60) as in the fourth embodiment.

  According to the present disclosure, for example, when the oxygen concentration recovery operation is performed before the storage door (1) such as a container is opened, a high oxygen concentration gas having a higher oxygen concentration than the atmosphere is supplied to the internal space having a low oxygen concentration. Is done. Therefore, the rate of increase of the oxygen concentration in the internal space becomes faster than when only the ventilation is performed and the atmosphere is introduced into the internal space. In addition, when the atmosphere (oxygen concentration of about 21%) is introduced into the internal space by simple ventilation, the air in the internal space is long enough to be replaced with the atmosphere in order to return the internal space to an oxygen concentration equivalent to the air. Whereas time is required, according to the present disclosure, by introducing a high oxygen concentration gas having a higher oxygen concentration than the atmosphere into the internal space, the time for returning the internal space to the oxygen concentration equivalent to the air is shortened compared to the conventional case. it can.

  According to the second aspect, for example, when the oxygen concentration recovery operation is performed before the storage door (1) such as a container is opened, the high oxygen concentration gas having a higher oxygen concentration than the atmosphere has a low oxygen concentration. At the same time, ventilation is performed and air is also introduced into the interior space. In this second aspect, ventilation is also performed during the oxygen concentration recovery operation, and the high oxygen concentration gas supplied to the internal space is mixed with the atmosphere so that everything is generated by the gas composition control unit (40, 60). Energy saving can be achieved as compared with the case of using oxygen concentration gas.

  According to the third aspect, the first composition adjustment unit (40) that separates nitrogen and oxygen from outside air in the storage (1) to generate a low oxygen concentration gas and a high oxygen concentration gas is used. By supplying the high oxygen concentration gas to the internal space of the storage (1) during the oxygen concentration recovery operation, the time for returning the internal space to the oxygen concentration equivalent to the atmosphere can be shortened compared to the conventional case.

  According to the fourth aspect, the first composition adjusting unit (40) that separates nitrogen and oxygen from outside air of the storage (1) to generate a low oxygen concentration gas and a high oxygen concentration gas, and storage During the oxygen concentration recovery operation using the second composition adjustment unit (60) that separates nitrogen, oxygen and carbon dioxide from the air in the chamber (1) to generate a low oxygen concentration gas and a high oxygen concentration gas. By supplying the high oxygen concentration gas to the internal space of the storage (1), it is possible to shorten the time for returning the internal space to the oxygen concentration equivalent to the atmosphere.

  According to the fifth aspect, the second composition adjusting unit (60) is used to supply the high oxygen concentration gas to the internal space of the storage (1) during the oxygen concentration recovery operation, so that the internal space is air The time for returning to a considerable oxygen concentration can be shortened compared to the conventional case.

Drawing 1 is an outline sectional view of the container for transportation provided with the air conditioner in a warehouse of an embodiment. FIG. 2 is a refrigerant circuit diagram showing the configuration of the refrigerant circuit of the container refrigerator provided in the shipping container. FIG. 3 is a piping system diagram showing the configuration of the internal air conditioner of the embodiment. FIG. 4 is a schematic cross-sectional view of a separation module provided in the internal air conditioner of the embodiment. FIG. 5 is a block diagram illustrating an oxygen concentration reduction operation performed by the internal air conditioner of the embodiment. FIG. 6 is a block diagram illustrating a carbon dioxide concentration reduction operation performed by the internal air conditioner of the embodiment. FIG. 7 is a block diagram illustrating an oxygen concentration recovery operation performed by the internal air conditioner of the embodiment. FIG. 8 is a block diagram illustrating another example of the oxygen concentration recovery operation performed by the internal air conditioner of the embodiment. FIG. 9 is a piping system diagram illustrating the configuration of the internal air conditioner according to the second embodiment. FIG. 10 is a piping system diagram of the internal air conditioner illustrating a state during the first operation of the first composition adjustment unit of the second embodiment. FIG. 11 is a piping system diagram of the internal air conditioner illustrating a state during the second operation of the first composition adjustment unit of the second embodiment.

  Embodiments will be described in detail with reference to the drawings. The embodiments and modifications described below are essentially preferable examples, and are not intended to limit the scope of the present disclosure, its application, or its use.

Embodiment 1
The internal air conditioner (30) of the present embodiment is provided in the transport container (1) for so-called CA (Controlled Atmosphere) transport. The internal air conditioner (30) adjusts the composition of the air in the internal container (inner space) in the transport container (1) so that it is different from the composition of the air in the external space, Or adjust to return to the composition.

As shown in FIG. 1, the transport container (1) constituting the storage is provided with a container body (2) and a container refrigerator (10). This transport container (1) is a reefer container capable of controlling the temperature in the warehouse. The internal air conditioner (30) of the present embodiment is installed in the container refrigerator (10). The transport container (1) is used for transporting as a cargo (6) a plant such as a respirable agricultural product that takes in oxygen (O ₂ ) in the air and releases carbon dioxide (CO ₂ ). Examples of plants include fruits such as bananas and avocados, vegetables, grains, bulbs, fresh flowers, and the like.

  The container body (2) is formed in an elongated rectangular parallelepiped box shape. One end surface of the container body (2) is open, and the container refrigerator (10) is attached so as to close the open end. The internal space of the container body (2) constitutes a cargo compartment (5) for storing cargo (6).

  A floor board (3) for placing the cargo (6) is arranged at the bottom of the cargo compartment (5). Between the floor plate (3) and the bottom plate of the container main body (2), an underfloor channel (4) for flowing the air blown out by the container refrigerator (10) is formed. The underfloor channel (4) is a channel extending in the longitudinal direction of the container body (2) along the bottom plate of the container body (2). One end of the underfloor channel (4) is connected to the outlet (27) of the container refrigerator (10), and the other end is the space above the floor plate (3) (that is, the space in which the cargo (6) is accommodated. ).

-Container refrigerator-
As shown in FIGS. 1 and 2, the container refrigerator (10) includes a casing (20), a refrigerant circuit (11) for performing a refrigeration cycle, an external fan (16), and an internal fan (17). And.

  The casing (20) includes an outer wall portion (21), an inner wall portion (22), a back plate (24), and a partition plate (25). As will be described later, the casing (20) is provided with a refrigerant circuit (11), an external fan (16), and an internal fan (17).

  The outer wall part (21) is a plate-like member arranged so as to cover the open end of the container body (2). The lower part of the outer wall part (21) bulges inside the container body (2). A warehouse inner wall part (22) is a plate-shaped member of the form along the warehouse outer wall part (21). The inner wall part (22) is arranged so as to cover the inner surface of the container main body (2) in the outer wall part (21). A space between the outer wall portion (21) and the inner wall portion (22) is filled with a heat insulating material (23).

  The casing (20) has a shape in which the lower part is recessed toward the inside of the container body (2). The lower part of the casing (20) forms an external equipment room (28) communicating with the external space of the transport container (1). An outside fan (16) is disposed in the outside equipment room (28).

  The back plate (24) is a substantially rectangular flat plate member. The back plate (24) is disposed inside the container body (2) with respect to the inner wall portion (22), and forms an inner air flow path (29) with the inner wall portion (22). The upper end of the internal air flow path (29) constitutes a suction port (26) of the casing (20), and the lower end thereof constitutes an air outlet (27) of the casing (20).

  The partition plate (25) is a plate-like member disposed so as to partition the internal air flow path (29) vertically. A partition plate (25) is arrange | positioned at the upper part of the internal air flow path (29). With this partition plate (25), the internal air flow path (29) becomes a primary flow path (29a) above the partition plate (25) and a secondary flow path (29b) below the partition plate (25). It is divided into. The primary channel (29a) communicates with the luggage compartment (5) through the suction port (26). The secondary flow path (29b) communicates with the underfloor flow path (4) through the air outlet (27). An internal fan (17) is attached to the partition plate (25). The internal fan (17) is arranged so as to blow out the air sucked from the primary flow path (29a) to the secondary flow path (29b).

  As shown in FIG. 2, the refrigerant circuit (11) is formed by connecting a compressor (12), a condenser (13), an expansion valve (14), and an evaporator (15) with piping. Closed circuit. When the compressor (12) is operated, the refrigerant circulates through the refrigerant circuit (11), and a vapor compression refrigeration cycle is performed. As shown in FIG. 1, the condenser (13) is arranged on the suction side of the external fan (16) in the external equipment room (28), and the evaporator (15) is the internal air flow path (29). In the secondary flow path (29b). Moreover, although illustration is abbreviate | omitted in FIG. 1, a compressor (12) is arrange | positioned at the external equipment room (28).

-In-house air conditioner-
As shown in FIG. 1, the internal air conditioner (30) includes a main unit (31), a sensor unit (90), a ventilation exhaust pipe (ventilation passage) (100), a controller (110), It has. The main unit (31) is installed in the external equipment room (28) of the container refrigerator (10). The sensor unit (90) is installed in the internal air flow path (29) of the shipping container (1). The ventilation exhaust pipe (100) is installed across the internal air flow path (29) and the external equipment room (28) of the transport container (1). The controller (110) is provided in the main unit (31) and controls the components of the internal air conditioner (30). Details of the sensor unit (90), the exhaust pipe (100) for ventilation, and the controller (110) will be described later.

  As shown in FIG. 3, the main body unit (31) of the internal air conditioner (30) includes a first composition adjustment unit (gas composition adjustment unit) (40) and a second composition adjustment unit (gas composition adjustment unit). (60), a pump unit (35), and a unit case (32). The unit case (32) is a box-shaped airtight container. The first composition adjustment unit (40), the second composition adjustment unit (60), and the pump unit (35) are arranged in the internal space of the unit case (32). Details of the first composition adjustment unit (40), the second composition adjustment unit (60), and the pump unit (35) will be described later.

  The internal air conditioner (30) includes a supply pipe (120), an internal suction pipe (75), and a measurement pipe (125). The supply pipe (120), the inside suction pipe (75), and the measurement pipe (125) are used to connect the main unit (31) to the internal air flow path (29) of the container refrigerator (10). It is piping.

  The supply pipe (120) is a pipe for supplying the air flowing out from the first composition adjustment unit (40) and the second composition adjustment unit (60) to the cargo compartment (5). The supply pipe (120) has an inlet end connected to the first composition adjustment section (40) and the second composition adjustment section (60), and an outlet end a secondary flow path (29b) of the internal air flow path (29). Open to.

  The inside suction pipe (75) is a pipe for supplying the inside air in the cargo compartment (5) to the second composition adjusting unit (60). The inside suction pipe (75) has an inlet end that opens to a secondary flow path (29b) of the internal air flow path (29), and an outlet end that is a second pump ( 37) connected. Note that, in the secondary flow path (29b) of the internal air flow path (29), the inlet end of the internal suction pipe (75) is arranged upstream of the outlet end of the supply pipe (120).

  The measurement pipe (125) is a pipe for supplying the air flowing through the supply pipe (120) to the sensor unit (90). The measurement pipe (125) has an inlet end connected to the supply pipe (120) and an outlet end connected to the sensor unit (90). The measurement pipe (125) is provided with a measurement on-off valve (126) made of an electromagnetic valve. This measurement on-off valve (126) is housed in the unit case (32) of the main unit (31).

  The ventilation exhaust pipe (100), the supply pipe (120), the internal suction pipe (75), the measurement pipe (125), and each composition adjustment section (40, 60) described later are provided. The piping (51 to 55, 57, 59, 71 to 74, 77, 79, 98) may be composed of a hard pipe, a flexible hose, or a pipe and a hose. You may be comprised by combining. In addition, each said piping (53-55, 73-75,120) is piping which comprises the gas path of this indication.

<Pumping unit>
As shown in FIG. 3, the pump unit (35) includes a first pump (36), a second pump (37), and a drive motor (38).

  Each of the first pump (36) and the second pump (37) is an air pump that discharges the sucked air. Each of the first pump (36) and the second pump (37) is constituted by a positive displacement fluid machine, for example. The first pump (36) and the second pump (37) are integrated. The drive motor (38) is an electric motor connected to the first pump (36) and the second pump (37). The drive motor (38) drives both the first pump (36) and the second pump (37).

<First composition adjustment unit>
The first composition adjustment unit (40) converts the outside air (untreated outside air) sucked from the outside of the transport container (1) into the first outside air (low oxygen concentration gas) and the second outside air ( High oxygen concentration gas). The 1st composition adjustment part (40) of this embodiment supplies the 1st exterior air which is supply air to a cargo compartment (5), and discharges the 2nd exterior air to the exterior of a transport container (1). To do.

  The first composition adjustment unit (40) includes an air filter (47), a first separation module (41), a first bypass valve (50), a first pressure sensor (45), and a first adjustment valve (46). And. In addition, the first composition adjustment section (40) includes an outside suction pipe (55), a first introduction pipe (52), a first primary side pipe (53), and a first secondary side pipe (54). And a first bypass pipe (51). Moreover, the 1st pump (36) of a pump unit (35) comprises this 1st composition adjustment part (40).

  The air filter (47) is a membrane filter for capturing dust or salt contained in the outside air. The air filter (47) is attached to the unit case (32) of the main unit (31). The air filter (47) is connected to the suction port of the first pump (36) via the outside suction pipe (55). In the internal air conditioner (30) of the present embodiment, the external intake pipe (55) is omitted, and the air filter (47) and the first air are connected via the internal space of the unit case (32) that is a sealed container. The pump (36) may be communicated.

  As will be described in detail later, the first separation module (41) includes a first inlet (42), a first primary outlet (43), and a first secondary outlet (44). The first introduction port (42) is connected to the discharge port of the first pump (36) via the first introduction pipe (52). The first primary outlet (43) is connected to the supply pipe (120) via the first primary pipe (53). One end of the first secondary pipe (54) is connected to the first secondary outlet (44). The first secondary pipe (54) extends to the outside of the unit case (32). The other end of the first secondary pipe (54) opens to the suction side of the external fan (16) in the external equipment room (28).

  The first bypass valve (50) is a switching valve having three ports and constitutes a first bypass valve mechanism. The first bypass valve (50) has a first state in which the first port communicates with the second port and is blocked from the third port (a state indicated by a solid line in FIG. 3), and the first port is in the first state. 3 is configured to be switched to a second state (a state indicated by a broken line in FIG. 3) that communicates with the third port and is blocked from the second port.

  The first bypass valve (50) is disposed in the middle of the first introduction pipe (52). The first bypass valve (50) has a first port connected to the discharge port of the first pump (36) and a second port connected to the first inlet (42) of the first separation module (41). . The inlet port of the first bypass pipe (51) is connected to the third port of the first bypass valve (50). The outlet end of the first bypass pipe (51) is connected to the first primary pipe (53). The first bypass pipe (51) constitutes a first bypass passage.

  The first pressure sensor (45) and the first control valve (46) are provided in the first primary side pipe (53). The first pressure sensor (45) and the first control valve (46) are closer to the first separation module (41) than the other end of the first bypass pipe (51) connected to the first primary pipe (53). Be placed. The first pressure sensor (45) is disposed closer to the first separation module (41) than the first control valve (46).

  The first pressure sensor (45) measures the pressure of the first outside air flowing out from the first primary outlet (43) of the first separation module (41). The measured value of the first pressure sensor (45) is substantially equal to the pressure of untreated outside air supplied from the first pump (36) to the first separation module (41).

  The first control valve (46) is an electric valve having a variable opening, and constitutes a first valve mechanism. When the opening degree of the first control valve (46) is changed, the pressure of the untreated outside air supplied from the first pump (36) to the first separation module (41) changes.

  The first separation module (41) constitutes a first separation unit. As will be described in detail later, the first separation module (41) includes a gas separation membrane (85). And the 1st separation module (41) is the untreated outside air, the 1st outside air (air which flows through the 1st primary side pipe (53)) which did not permeate the gas separation membrane (85), and gas It isolate | separates into the 2nd exterior air (air which flows through a 1st secondary side pipe | tube (54)) which permeate | transmitted the separation membrane (85).

  The first outdoor air has a higher nitrogen concentration than the untreated outdoor air and a lower oxygen concentration than the untreated outdoor air. The second outside air has a lower nitrogen concentration than the untreated outside air and a higher oxygen concentration than the untreated outside air. Thus, the 1st outside air and the 2nd outside air differ in the concentration of the substance which constitutes each. In addition, the density | concentration in this specification means a volume ratio.

  The first composition adjustment unit (40) includes a first primary side switching valve (56), a first primary side discharge pipe (57), a first secondary side switching valve (58), and a first second switching valve. A secondary supply pipe (59) is provided.

  Each of the first primary side switching valve (56) and the first secondary side switching valve (58) is a switching valve having three ports. Each of the first primary side switching valve (56) and the first secondary side switching valve (58) is in a first state in which the first port communicates with the second port and is blocked from the third port (see FIG. 3 is shown in FIG. 3 as a solid line) and a second state where the first port communicates with the third port and is blocked from the second port (shown by a broken line in FIG. 3). The

  The first primary side switching valve (56) is disposed in the middle of the first primary side pipe (53). In the first primary pipe (53), the first primary switching valve (56) is disposed closer to the supply pipe (120) than the outlet end of the first bypass pipe (51). The first primary switching valve (56) has a first port connected to the first control valve (46) and a second port connected to the supply pipe (120). One end of the first primary side discharge pipe (57) is connected to the third port of the first primary side switching valve (56). The other end of the first primary discharge pipe (57) is connected to the first secondary pipe (54).

  The first secondary side switching valve (58) is disposed in the middle of the first secondary side pipe (54). In the first secondary pipe (54), the first secondary switching valve (58) is disposed closer to the first separation module (41) than the other end of the first primary discharge pipe (57). The first secondary switching valve (58) has a first port connected to the first secondary outlet (44) of the first separation module (41) and a second port connected to the first secondary pipe. It communicates with the outside equipment room (28) of the shipping container (1) via (54). One end of the first secondary supply pipe (59) is connected to the third port of the first secondary switching valve (58). The other end of the first secondary supply pipe (59) is connected to the supply pipe (120).

<Second composition adjustment unit>
The second composition adjustment unit (60) uses the air in the cabinet (air in the untreated cabinet) sucked from the internal space of the transport container (1) as air in the first cabinet (low oxygen concentration gas) and air in the second cabinet. It is configured to be separated into (high oxygen concentration gas). The 2nd composition adjustment part (60) of this embodiment supplies the 1st warehouse air to the cargo compartment (5), and discharges the 2nd warehouse air which is discharge air to the exterior of a transport container (1). To do.

  The second composition adjustment unit (60) includes a second separation module (61), a second bypass valve (70), a second pressure sensor (65), and a second adjustment valve (66). The second composition adjustment unit (60) includes a second introduction pipe (72), a second primary pipe (73), a second secondary pipe (74), and a second bypass pipe (71). It has. The second pump (37) of the pump unit (35) constitutes the second composition adjustment unit (60).

  As will be described in detail later, the second separation module (61) includes a second inlet (62), a second primary outlet (63), and a second secondary outlet (64). The second introduction port (62) is connected to the discharge port of the second pump (37) via the second introduction pipe (72). The second primary side outlet (63) is connected to the supply pipe (120) via the second primary side pipe (73). One end of the second secondary pipe (74) is connected to the second secondary outlet (64). The second secondary pipe (74) extends to the outside of the unit case (32). The other end of the second secondary pipe (74) opens to the suction side of the external fan (16) in the external equipment room (28). Further, the inside suction pipe (75) is connected to the suction port of the second pump (37).

  The second bypass valve (70) is a switching valve having three ports and constitutes a second bypass valve mechanism. The second bypass valve (70) has a first state in which the first port communicates with the second port and is blocked from the third port (state indicated by a solid line in FIG. 3), and the first port is in the first state. 3 is configured to be switched to a second state (a state indicated by a broken line in FIG. 3) that communicates with the third port and is blocked from the second port.

  The second bypass valve (70) is disposed in the middle of the second introduction pipe (72). The second bypass valve (70) has a first port connected to the discharge port of the second pump (37) and a second port connected to the second introduction port (62) of the second separation module (61). . The inlet port of the second bypass pipe (71) is connected to the third port of the second bypass valve (70). The outlet end of the second bypass pipe (71) is connected to the second primary pipe (73). The second bypass pipe (71) constitutes a second bypass passage.

  The second pressure sensor (65) and the second control valve (66) are provided in the second primary pipe (73). The second pressure sensor (65) and the second control valve (66) are closer to the second separation module (61) than the other end of the second bypass pipe (71) connected to the second primary pipe (73). Be placed. The second pressure sensor (65) is disposed closer to the second separation module (61) than the second control valve (66).

  The second pressure sensor (65) measures the pressure of the second outside air flowing out from the second primary side outlet (63) of the second separation module (61). The measured value of the second pressure sensor (65) is substantially equal to the pressure of the untreated internal air supplied from the second pump (37) to the second separation module (61).

  The second control valve (66) is an electric valve having a variable opening, and constitutes a second valve mechanism. When the opening degree of the second control valve (66) is changed, the pressure of the untreated storage air supplied from the second pump (37) to the second separation module (61) changes.

  The second separation module (61) constitutes a second separation unit. As will be described in detail later, the second separation module (61) includes a gas separation membrane (85). Then, the second separation module (61) converts the untreated internal air into the first internal air that has not permeated the gas separation membrane (85) (air flowing through the second primary side pipe (73)), gas It isolate | separates into the 2nd interior air (air which flows through a 2nd secondary side pipe | tube (74)) permeate | transmitted the separation membrane (85).

  The first internal air has a higher nitrogen concentration than the untreated internal air, and an oxygen concentration and a carbon dioxide concentration lower than the untreated internal air. The second internal air has a lower nitrogen concentration than the untreated internal air, and an oxygen concentration and a carbon dioxide concentration higher than the untreated internal air. As described above, the first indoor air and the second indoor air have different concentrations of substances constituting each of them.

  The second composition adjusting unit (60) includes a second primary switching valve (76), a second primary discharge pipe (77), a second secondary switching valve (78), and a second secondary switching valve (76). A secondary supply pipe (79) is provided.

  Each of the second primary side switching valve (76) and the second secondary side switching valve (78) is a switching valve having three ports. Each of the second primary side switching valve (76) and the second secondary side switching valve (78) is in a first state in which the first port communicates with the second port and is blocked from the third port (see FIG. 3 is shown in FIG. 3 as a solid line) and a second state where the first port communicates with the third port and is blocked from the second port (shown by a broken line in FIG. 3). The

  The second primary side switching valve (76) is disposed in the middle of the second primary side pipe (73). In the second primary side pipe (73), the second primary side switching valve (76) is disposed closer to the supply pipe (120) than the outlet end of the second bypass pipe (71). The second primary side switching valve (76) has a first port connected to the second control valve (66) and a second port connected to the supply pipe (120). One end of the second primary side discharge pipe (77) is connected to the third port of the second primary side switching valve (76). The other end of the second primary side discharge pipe (77) is connected to the second secondary side pipe (74).

  The second secondary side switching valve (78) is disposed in the middle of the second secondary side pipe (74). In the second secondary side pipe (74), the second secondary side switching valve (78) is disposed closer to the second separation module (61) than the other end of the second primary side discharge pipe (77). The second secondary switching valve (78) has a first port connected to the second secondary outlet (64) of the second separation module (61), and the second port connected to the second secondary pipe. It communicates with the outside equipment room (28) of the shipping container (1) via (74). One end of the second secondary supply pipe (79) is connected to the third port of the second secondary switching valve (78). The other end of the second secondary supply pipe (79) is connected to the supply pipe (120).

<Separation module>
The structures of the first separation module (41) and the second separation module (61) will be described with reference to FIG. The first separation module (41) and the second separation module (61) have the same structure.

  Each separation module (41, 61) includes one cylindrical case (80) and two partition walls (81a, 81b). The cylindrical case (80) is an elongated cylindrical container with both ends closed. The partition walls (81a, 81b) are members for partitioning the internal space of the cylindrical case (80), and are provided so as to cross the internal space of the cylindrical case (80). The partition walls (81a, 81b) are arranged one by one at a position near one end and a position near the other end of the internal space of the cylindrical case (80). In FIG. 4, the internal space of the cylindrical case (80) is a secondary space located between the introduction chamber (82) located on the left side of the left partition wall (81a) and the two partition walls (81a, 81b). It is partitioned into a side outlet chamber (84) and a primary outlet chamber (83) located on the right side of the right partition wall (81b).

  Each separation module (41, 61) includes a number of gas separation membranes (85) formed in a hollow fiber shape (that is, a very thin tube having an outer diameter of 1 mm or less). The hollow fiber gas separation membrane (85) is provided from one partition wall portion (81a) to the other partition wall portion (81b). Each gas separation membrane (85) has one end passing through one partition wall (81a) and opening into the introduction chamber (82), and the other end passing through the other partition wall (81b) and leading out to the primary side. Open to chamber (83). In the internal space of the cylindrical case (80), the portion outside the gas separation membrane (85) in the space between the two partition walls (81a, 81b) constitutes the secondary outlet chamber (84). . In each separation module (41, 61), the introduction chamber (82) and the primary side outlet chamber (83) communicate with each other via a hollow fiber gas separation membrane (85), while the secondary side outlet chamber (84) , The space inside the gas separation membrane (85), the introduction chamber (82), and the primary outlet chamber (83) are not in communication.

  The cylindrical case (80) is provided with an inlet (42, 62), a primary outlet (43, 63), and a secondary outlet (44, 64). The introduction port (42, 62) is disposed at the left end of the cylindrical case (80) in FIG. 4 and communicates with the introduction chamber (82). The primary side outlet (43, 63) is disposed at the right end of the cylindrical case (80) in FIG. 4 and communicates with the primary side outlet chamber (83). The secondary side outlet (44, 64) is disposed in the longitudinal middle portion of the cylindrical case (80) and communicates with the secondary side outlet chamber (84).

  The gas separation membrane (85) is a non-porous membrane made of a polymer. This gas separation membrane (85) separates the components contained in the mixed gas by utilizing the fact that the rate at which molecules permeate the gas separation membrane (85) (permeation rate) differs for each substance.

  In the internal air conditioner (30) of this embodiment, the same gas separation membrane (85) is provided in each of the first separation module (41) and the second separation module (61). The gas separation membrane (85) of each separation module (41, 61) has a characteristic that the permeation rate of nitrogen is lower than both the permeation rate of oxygen and the permeation rate of carbon dioxide. The hollow fiber-shaped gas separation membranes (85) have substantially the same film thickness. Therefore, the gas separation membrane (85) provided in each separation module (41, 61) has a characteristic that the permeability of nitrogen is lower than both the permeability of oxygen and the permeability of carbon dioxide.

  In each separation module (41, 61), the air flowing into the introduction chamber (82) through the introduction port (42, 62) passes through the space inside the hollow fiber gas separation membrane (85) to the primary side outlet chamber ( 83) Part of the air flowing through the space inside the gas separation membrane (85) passes through the gas separation membrane (85) and moves to the secondary outlet chamber (84), and the rest flows to the primary outlet chamber (83). Flow into.

  The gas separation membrane (85) of each separation module (41, 61) has a lower nitrogen permeability than oxygen and carbon dioxide. That is, nitrogen is less permeable to the gas separation membrane (85) than oxygen and carbon dioxide. For this reason, as the air flowing inside the hollow fiber-like gas separation membrane (85) approaches the primary side outlet chamber (83), the nitrogen concentration rises and at the same time the oxygen concentration and carbon dioxide concentration fall. Further, oxygen and carbon dioxide contained in the air flowing through the hollow fiber gas separation membrane (85) permeate the gas separation membrane (85) and move to the secondary side outlet chamber (84).

  As a result, the air that has flowed into the primary outlet chamber (83) without passing through the gas separation membrane (85) has a higher nitrogen concentration than the air in the introduction chamber (82). Is lower than the air in the introduction chamber (82). The air that has passed through the gas separation membrane (85) and moved to the secondary outlet chamber (84) has a lower nitrogen concentration than the air in the introduction chamber (82), and its oxygen concentration and carbon dioxide concentration are lower. It becomes higher than the air in the introduction chamber (82).

  In the first separation module (41), the untreated outside air flows from the first introduction port (42) into the introduction chamber (82), and does not pass through the gas separation membrane (85), thereby leading to the primary outlet chamber (83). The air that has flowed into the second chamber flows out from the first primary outlet port (43) as the first external air, passes through the gas separation membrane (85), and flows into the secondary outlet chamber (84). It flows out from the first secondary outlet (44) as outside air. On the other hand, in the second separation module (61), the air in the untreated cabinet flows from the second introduction port (62) into the introduction chamber (82), and does not pass through the gas separation membrane (85). 83) The air that flows into the first chamber flows out from the second primary outlet (63), passes through the gas separation membrane (85), and flows into the secondary outlet (84) as the first internal air. It flows out from the second secondary outlet (64) as air in the two cabinets.

<Sensor unit>
As shown in FIGS. 1 and 3, the sensor unit (90) is arranged in the secondary flow path (29b) of the internal air flow path (29) of the container refrigerator (10). As shown in FIG. 3, the sensor unit (90) includes an oxygen sensor (91) that measures the oxygen concentration of a mixed gas such as air, and a carbon dioxide sensor (95) that measures the carbon dioxide concentration of the mixed gas such as air. With.

  The oxygen sensor (91) includes a sensor body (92) that is a galvanic cell type sensor, and a sensor case (93) that houses the sensor body (92). An air filter (94) for introducing the internal air flowing through the internal air flow path (29) into the internal space of the sensor case (93) is attached to the sensor case (93). The air filter (94) is a membrane filter for capturing dust and the like contained in the internal air. Further, the outlet end of the measurement pipe (125) is connected to the sensor case (93).

  The carbon dioxide sensor (95) includes a sensor body (96) that is a non-dispersive infrared (NDIR) type sensor and a sensor case (97) that houses the sensor body (96). . The internal space of the sensor case (97) communicates with the internal space of the sensor case (93) of the oxygen sensor (91) through a pipe. Further, one end of an outlet pipe (98) is connected to the sensor case (97). The other end of the outlet pipe (98) opens to the primary flow path (29a) of the internal air flow path (29).

  As will be described later, during operation of the internal fan (17), the atmospheric pressure in the secondary flow path (29b) is slightly higher than the atmospheric pressure in the primary flow path (29a). For this reason, in the state where the on-off valve for measurement (126) is closed, the internal air of the secondary flow path (29b) flows into the oxygen sensor (91) through the air filter (94), and then the carbon dioxide sensor. After passing through (95), it flows into the primary flow path (29a) through the outlet pipe (98). In this state, in the sensor unit (90), the oxygen sensor (91) measures the oxygen concentration of the inside air, and the carbon dioxide sensor (95) measures the carbon dioxide concentration of the inside air.

<Ventilation exhaust pipe>
The ventilation exhaust pipe (100) is a pipe for connecting the inside and the outside of the transport container (1). The ventilation exhaust pipe (100) constitutes a ventilation exhaust passage. As shown in FIG. 1, the ventilation exhaust pipe (100) penetrates the casing (20) of the container refrigerator (10). One end of the ventilation exhaust pipe (100) opens to the secondary flow path (29b) of the internal air flow path (29). The other end of the ventilation exhaust pipe (100) opens to the suction side of the external fan (16) in the external equipment room (28).

  As shown in FIG. 3, an air filter (102) is attached to one end of the ventilation exhaust pipe (100). The air filter (102) is a membrane filter for capturing dust and the like contained in the internal air. The ventilation exhaust pipe (100) is provided with a ventilation exhaust valve (101). The ventilation exhaust valve (101) is an on-off valve composed of an electromagnetic valve.

<Controller>
The controller (110) includes a CPU (111) that performs a control operation and a memory (112) that stores data necessary for the control operation. The controller (110) receives the measured values of the oxygen sensor (91), the carbon dioxide sensor (95), the first pressure sensor (45), and the second pressure sensor (65). The controller (110) includes a pump unit (35), a first control valve (46), a second control valve (66), a first bypass valve (50), a second bypass valve (70), and a ventilation exhaust valve. A control operation for operating (101) is performed. The CPU (111) also functions as an oxygen concentration recovery control unit that performs an oxygen concentration recovery operation, which will be described later, to return the oxygen concentration in the chamber to a concentration corresponding to the atmosphere.

-Operation of container refrigerator-
The container refrigerator (10) performs a cooling operation for cooling the air in the container of the transport container (1).

  In the cooling operation, the compressor (12) of the refrigerant circuit (11) is operated, and the refrigerant is circulated in the refrigerant circuit (11) to perform a vapor compression refrigeration cycle. In the refrigerant circuit (11), the refrigerant discharged from the compressor (12) sequentially passes through the condenser (13), the expansion valve (14), and the evaporator (15), and then to the compressor (12). Inhaled and compressed.

  In the cooling operation, the outside fan (16) and the inside fan (17) are operated. When the outside fan (16) is activated, outside air outside the transport container (1) is sucked into the outside equipment room (28) and passes through the condenser (13). In the condenser (13), the refrigerant dissipates heat to the outside air and condenses. When the internal fan (17) is activated, the internal air in the cargo compartment (5) of the transport container (1) is drawn into the internal air flow path (29) and passes through the evaporator (15). In the evaporator (15), the refrigerant absorbs heat from the internal air and evaporates.

  The flow of the internal air will be described. The internal air in the cargo compartment (5) flows into the primary air flow path (29a) of the internal air flow path (29) through the suction port (26), and then flows into the secondary flow by the internal fan (17). It is blown out to the road (29b). The internal air flowing into the secondary channel (29b) is cooled when passing through the evaporator (15), and then blown from the outlet (27) to the underfloor channel (4). 4) Pass through the cargo compartment (5).

  In the internal air flow path (29), the primary flow path (29a) is located on the suction side of the internal fan (17), and the secondary flow path (29b) is located on the blow-out side of the internal fan (17). . For this reason, during operation of the internal fan (17), the atmospheric pressure in the secondary flow path (29b) is slightly higher than the atmospheric pressure in the primary flow path (29a).

-Operation of the air conditioner in the cabinet-
The internal air conditioner (30) adjusts the composition of the internal air in the cargo compartment (5) of the transport container (1) (in this embodiment, the oxygen concentration and the carbon dioxide concentration of the internal air). Do the operation. Here, regarding the operation of the internal air conditioner (30) of the present embodiment, the target range of the oxygen concentration of the internal air is 5% ± 1%, and the target range of the carbon dioxide concentration of the internal air is 2 A case of% ± 1% will be described as an example.

<Overview of operation of internal air conditioner>
The interior air conditioner (30) of the present embodiment includes an oxygen concentration reduction operation for reducing the oxygen concentration of the interior air in the cargo compartment (5), and a dioxide dioxide in the interior air in the cargo compartment (5). A carbon dioxide concentration reduction operation for decreasing the carbon concentration and an oxygen concentration increase operation for increasing the oxygen concentration of the air inside the cargo compartment (5) are performed.

  At the time when loading of the cargo (6) into the transport container (1) is completed, the composition of the air inside the cargo compartment (5) is the composition of the atmosphere (nitrogen concentration: 78%, oxygen concentration: 21 %, Carbon dioxide concentration: 0.04%). Therefore, the internal air conditioner (30) performs an oxygen concentration reduction operation for reducing the oxygen concentration of the internal air. When the oxygen concentration of the internal air reaches the upper limit (6%) of the target range, the internal air conditioner (30) stops the oxygen concentration reducing operation.

  After the oxygen concentration of the air inside the warehouse reaches 6% and the oxygen concentration stopping operation of the air conditioner (30) in the warehouse is stopped, the plant that is the cargo (6) breathes and the oxygen concentration in the air inside the warehouse At the same time, the carbon dioxide concentration of the internal air gradually increases.

  When the carbon dioxide concentration of the internal air reaches the upper limit (3%) of the target range, the internal air conditioner (30) performs a carbon dioxide concentration reduction operation for reducing the carbon dioxide concentration of the internal air. . When the carbon dioxide concentration in the internal air reaches the lower limit (1%) of the target range, the internal air conditioner (30) stops the carbon dioxide concentration reducing operation.

  When the oxygen concentration of the internal air reaches the lower limit (4%) of the target range, the internal air conditioner (30) performs an oxygen concentration increasing operation for increasing the oxygen concentration of the internal air. When the oxygen concentration of the internal air reaches the upper limit (6%) of the target range, the internal air conditioner (30) stops the oxygen concentration increasing operation.

  Thus, the internal air conditioner (30) performs the oxygen concentration reduction operation to reduce the oxygen concentration of the internal air in the cargo compartment (5) from 21% (atmospheric oxygen concentration) to the target range. Do. In addition, the internal air conditioner (30) operates to reduce carbon dioxide and increase oxygen concentration in order to maintain the oxygen concentration and carbon dioxide concentration of the air in the cargo compartment (5) within their target ranges. And repeating appropriately.

<Oxygen concentration reduction operation>
The oxygen concentration reduction operation of the internal air conditioner (30) will be described with reference to FIGS. In this oxygen concentration reduction operation, the first composition adjustment unit (40) supplies the first outdoor air having a low oxygen concentration to the cargo compartment (5), and the second composition adjustment unit (60) has the first low oxygen concentration. Supply the air in the warehouse to the cargo compartment (5).

  In the oxygen concentration reduction operation, the controller (110) sets each of the first bypass valve (50) and the second bypass valve (70) to the first state (the state indicated by the solid line in FIG. 3), and the pump unit ( The drive motor (38) of 35) is energized to operate the first pump (36) and the second pump (37), and the ventilation exhaust valve (101) is set to the open state. The first primary side switching valve (56), the first secondary side switching valve (58), the second primary side switching valve (76), and the second secondary side switching valve (78) are all in the first state. Set to.

  First, when the first pump (36) is operated, the outside air existing outside the transport container (1) passes through the air filter (47) and the outside suction pipe (55), and the first pump (36). Sucked into. The first pump (36) pressurizes and discharges the sucked outside air. The pressure of the outside air discharged from the first pump (36) is about twice the atmospheric pressure. The outside air discharged from the first pump (36) flows through the first introduction pipe (52) and flows into the first introduction port (42) of the first separation module (41) as untreated outside air.

  In the first separation module (41), the untreated outside air that has flowed into the introduction chamber (82) through the first introduction port (42) flows into the hollow fiber gas separation membrane (85). A part of the air flowing inside the hollow fiber gas separation membrane (85) passes through the gas separation membrane (85) and moves to the secondary outlet chamber (84) as the second outside air, and the rest It flows into the primary outlet chamber (83) as the first outside air. As described above, the gas separation membrane (85) has a characteristic that nitrogen permeability is lower than oxygen permeability. For this reason, as shown in FIG. 5, the oxygen concentration of the first outdoor air is lower than the oxygen concentration of the untreated outdoor air, and the oxygen concentration of the second outdoor air is the oxygen concentration of the untreated outdoor air. Higher than.

  The first outdoor air that has flowed out from the first primary outlet (43) of the first separation module (41) into the first primary pipe (53) flows into the supply pipe (120). On the other hand, the second outside air flowing out from the first secondary outlet (44) of the first separation module (41) to the first secondary pipe (54) is discharged to the outside of the transport container (1). Is done.

  Next, when the second pump (37) is actuated, the internal air present inside the transport container (1) (specifically, the secondary flow path (29b) of the container refrigerator (10)) The air is sucked into the second pump (37) through the inside suction pipe (75). The second pump (37) pressurizes and discharges the sucked internal air. The pressure of the outside air discharged from the second pump (37) is slightly higher than the atmospheric pressure. The inside air discharged from the second pump (37) flows through the second introduction pipe (72) and flows into the second introduction port (62) of the second separation module (61) as untreated inside air.

  In the second separation module (61), the untreated internal air that has flowed into the introduction chamber (82) through the second introduction port (62) flows into the hollow fiber gas separation membrane (85). Part of the air flowing inside the hollow fiber gas separation membrane (85) passes through the gas separation membrane (85) and moves to the secondary outlet chamber (84) as second internal air, and the rest It flows into the primary outlet chamber (83) as the first internal air. As described above, the gas separation membrane (85) has a characteristic that nitrogen permeability is lower than oxygen permeability. Therefore, as shown in FIG. 5, the oxygen concentration of the first indoor air is lower than the oxygen concentration of the untreated outdoor air, and the oxygen concentration of the second internal air is the oxygen concentration of the untreated outdoor air. Higher than.

  The first internal air that has flowed out of the second primary side outlet (63) of the second separation module (61) into the second primary side pipe (73) flows into the supply pipe (120). On the other hand, the air in the second cabinet that flows out from the second secondary outlet (64) of the second separation module (61) to the second secondary pipe (74) is discharged to the outside of the transport container (1). Is done.

  As described above, the first outside air flowing out from the first separation module (41) and the first inside air flowing out from the second separation module (61) flow into the supply pipe (120). The mixed air of the first outside air and the first inside air flowing through the supply pipe (120) flows into the secondary flow path (29b) of the container refrigerator (10), and the secondary flow path (29b ) Is supplied to the cargo compartment (5) together with the air flowing through.

  Normally, during the oxygen concentration reduction operation, the flow rate Qo1 of the first outside air supplied from the outside to the inside of the transport container (1) is discharged from the inside of the transport container (1) to the outside. It is larger than the flow rate Qi2 of the internal air (Qo1> Qi2), and the atmospheric pressure in the transport container (1) becomes a positive pressure (see FIG. 5). That is, the first composition adjusting unit (40) supplies the first outside air to the inside of the transport container (1) so that the atmospheric pressure in the transport container (1) becomes a positive pressure. Since the atmospheric pressure in the transport container (1) is positive, a part of the air in the warehouse is discharged to the outside of the transport container (1) through the ventilation exhaust pipe (100).

  As described above, in the oxygen concentration reduction operation, the first outside air having a lower oxygen concentration than the atmosphere is supplied, and at the same time, the inside air in the cargo compartment (5) is transported through the ventilation exhaust pipe (100). Drain outside (1) and reduce the oxygen concentration in the air in the storage compartment (5). In the oxygen concentration reduction operation, the air in the second compartment with high oxygen concentration separated from the air in the untreated warehouse is discharged to the outside of the transport container (1), so that the inside of the cargo compartment (5) Reduce oxygen concentration in air.

<CO2 concentration reduction operation>
The carbon dioxide concentration reduction operation of the internal air conditioner (30) will be described with reference to FIGS. 3, 4, and 6 as appropriate. In this carbon dioxide reduction operation, the first composition adjustment unit (40) supplies the first outside air having a low oxygen concentration to the cargo compartment (5), and the second composition adjustment unit (60) has a low carbon dioxide concentration. Supply the air in one warehouse to the cargo room (5).

  In the carbon dioxide concentration reduction operation, the controller (110) sets each of the first bypass valve (50) and the second bypass valve (70) to the first state (the state indicated by the solid line in FIG. 3), and the pump unit. The drive motor (38) of (35) is energized to operate the first pump (36) and the second pump (37), the ventilation exhaust valve (101) is set to the open state, and the measurement on-off valve (126 ) Is closed. The first primary side switching valve (56), the first secondary side switching valve (58), the second primary side switching valve (76), and the second secondary side switching valve (78) are all in the first state. Set to. And in each of a 1st composition adjustment part (40) and a 2nd composition adjustment part (60), air flows similarly to oxygen concentration reduction operation | movement. However, in the carbon dioxide concentration reduction operation, the pressure of the outside air discharged by the first pump (36) and the pressure of the inside air discharged by the second pump (37) are both slightly higher than the atmospheric pressure. It is.

  In the first composition adjustment unit (40), the untreated outside air that has flowed into the first separation module (41) has a higher nitrogen concentration and a lower oxygen concentration than the untreated outside air, It is separated into second outdoor air having a lower nitrogen concentration and a higher oxygen concentration than untreated outdoor air. Then, the first outside air is supplied to the inside of the transport container (1), and the second outside air is discharged to the outside of the transport container (1). Note that the carbon dioxide concentration in the untreated outside air is substantially the same as the atmospheric carbon dioxide concentration (0.04%). For this reason, the carbon dioxide concentration of the first outdoor air can be regarded as substantially zero.

  In the second composition adjustment unit (60), the untreated cabinet air that has flowed into the second separation module (61) has a higher nitrogen concentration and lower oxygen and carbon dioxide concentrations than the untreated cabinet air. The internal air is separated into the second internal air having a lower nitrogen concentration and a higher oxygen concentration and carbon dioxide concentration than the untreated internal air. Then, the first internal air is supplied to the inside of the transport container (1), and the second internal air is discharged to the outside of the transport container (1).

  Normally, during the carbon dioxide concentration reduction operation, as in the oxygen concentration reduction operation, the flow rate Qo1 of the first outside air is larger than the flow rate Qi2 of the second inside air (Qo1> Qi2). The atmospheric pressure in the container (1) becomes a positive pressure (see FIG. 6). That is, the first composition adjusting unit (40) supplies the first outside air to the inside of the transport container (1) so that the atmospheric pressure in the transport container (1) becomes a positive pressure. Because the atmospheric pressure in the transport container (1) is positive, a part of the air in the cargo compartment (5) passes through the ventilation exhaust pipe (100) to the outside of the transport container (1). Discharged.

  As described above, in the operation of reducing the carbon dioxide concentration, the first outside air having an extremely low carbon dioxide concentration is supplied, and at the same time, the inside air is discharged to the outside of the transport container (1) through the ventilation exhaust pipe (100). Reduce the carbon dioxide concentration of the air inside the cargo compartment (5). In the carbon dioxide concentration reduction operation, the air in the second compartment with high carbon dioxide concentration separated from the air in the untreated warehouse is discharged outside the transport container (1), so that the inside of the cargo compartment (5) Decrease the carbon dioxide concentration of the air in the cabinet.

<Oxygen concentration increasing operation>
The oxygen concentration increasing operation of the internal air conditioner (30) will be described with reference to FIG. In this oxygen concentration increasing operation, the first composition adjustment unit (40) supplies the outside air sucked from the outside of the transport container (1) to the cargo compartment (5) as it is, and the second composition adjustment unit (60) The inside air sucked from the inside of the transport container (1) is sent back to the cargo compartment (5).

  In the oxygen concentration increasing operation, the controller (110) sets each of the first bypass valve (50) and the second bypass valve (70) to the second state (the state indicated by the broken line in FIG. 3), and the pump unit ( The drive motor (38) of 35) is energized to operate the first pump (36) and the second pump (37), the ventilation exhaust valve (101) is set to the open state, and the measurement on-off valve (126) Set to closed. The first primary side switching valve (56), the first secondary side switching valve (58), the second primary side switching valve (76), and the second secondary side switching valve (78) are all in the first state. Set to.

  In the first composition adjustment unit (40), the outside air discharged from the first pump (36) flows into the first bypass pipe (51) and maintains the nitrogen concentration and oxygen concentration in the first primary state. It flows into the side pipe (53) and then is supplied to the inside of the transport container (1) through the supply pipe (120). On the other hand, in the 2nd composition adjustment part (60), after the in-compartment air suck | inhaled by the 2nd pump (37) is discharged from the 2nd pump (37), it passes through a 2nd bypass pipe (71), and is 2nd. It flows into the primary pipe (73), and then returns to the inside of the transport container (1) through the supply pipe (120). A part of the air in the cargo compartment (5) is discharged to the outside of the transport container (1) through the ventilation exhaust pipe (100).

  As described above, in the oxygen concentration increasing operation, the oxygen concentration in the cargo compartment (5) is increased by supplying the outside air having a higher oxygen concentration than the inside air to the inside of the transport container (1).

-Control action of controller-
The controller (110) of the internal air conditioner (30) monitors the measured values of the oxygen sensor (91) and the carbon dioxide sensor (95). And the oxygen sensor (91) and the carbon dioxide sensor so that the oxygen concentration and the carbon dioxide concentration of the air in the warehouse are kept in the respective target ranges by the operation of the air conditioning device (30) in the warehouse described above. The components of the air conditioner (30) in the cabinet are controlled based on the measured value of (95).

  By the way, when taking out agricultural products and other items that have been transported or stored in the container (1), ventilate to return the oxygen concentration in the air to the atmosphere before opening the container (1) door. However, it takes a long time to ventilate alone to raise the oxygen concentration of the air in the cabinet to about 21% equivalent to the atmosphere. Therefore, in this embodiment, the time for returning the inside air to the atmosphere is reduced by performing the oxygen concentration recovery operation (oxygen concentration recovery operation).

<Oxygen concentration recovery operation>
The oxygen concentration recovery operation of the internal air conditioner (30) will be described with reference to FIGS.

  In the oxygen concentration recovery operation, the controller (110) sets each of the first bypass valve (50) and the second bypass valve (70) to the first state (the state indicated by a solid line in FIG. 3), and the pump unit ( The drive motor (38) of 35) is energized to operate the first pump (36) and the second pump (37), and the ventilation exhaust valve (101) is set to the open state. The above state is the same as the oxygen concentration reduction operation. On the other hand, the first primary side switching valve (56), the first secondary side switching valve (58), the second primary side switching valve (76), and the second secondary side switching valve (78) are all in the second state. Set to.

  First, when the first pump (36) is operated, the outside air existing outside the transport container (1) passes through the air filter (47) and the outside suction pipe (55), and the first pump (36). Sucked into. The first pump (36) pressurizes and discharges the sucked outside air. The pressure of the outside air discharged from the first pump (36) is about twice the atmospheric pressure. The outside air discharged from the first pump (36) flows through the first introduction pipe (52) and flows into the first introduction port (42) of the first separation module (41) as untreated outside air.

  In the first separation module (41), the untreated outside air that has flowed into the introduction chamber (82) through the first introduction port (42) flows into the hollow fiber gas separation membrane (85). A part of the air flowing inside the hollow fiber gas separation membrane (85) passes through the gas separation membrane (85), and the oxygen concentration is higher than the oxygen concentration of the untreated outdoor air. It moves to the secondary outlet chamber (84), and the remainder flows into the primary outlet chamber (83) as the first outdoor air whose oxygen concentration is lower than the oxygen concentration of the untreated outdoor air.

  The first outside air flowing out from the first primary outlet (43) of the first separation module (41) to the first primary pipe (53) is supplied from the first primary switching valve (56) to the first secondary. It flows out to the side pipe (54) and is discharged outside the shipping container (1). On the other hand, the second outside air flowing out from the first secondary outlet (44) of the first separation module (41) to the first secondary pipe (54) is the first secondary switching valve (58). To the supply pipe (120) through the first secondary supply pipe (59).

  Next, when the second pump (37) is actuated, the internal air present inside the transport container (1) (specifically, the secondary flow path (29b) of the container refrigerator (10)) The air is sucked into the second pump (37) through the inside suction pipe (75). The second pump (37) pressurizes and discharges the sucked internal air. The pressure of the outside air discharged from the second pump (37) is slightly higher than the atmospheric pressure. The inside air discharged from the second pump (37) flows through the second introduction pipe (72) and flows into the second introduction port (62) of the second separation module (61) as untreated inside air.

  In the second separation module (61), the untreated internal air that has flowed into the introduction chamber (82) through the second introduction port (62) flows into the hollow fiber gas separation membrane (85). The air flowing inside the hollow fiber-shaped gas separation membrane (85) partially passes through the gas separation membrane (85), and the oxygen concentration is higher than the oxygen concentration of the untreated outside air as the second indoor air. It moves to the secondary side outlet chamber (84), and the remainder flows into the primary side outlet chamber (83) as the first internal air whose oxygen concentration is lower than the oxygen concentration of the untreated outdoor air.

  The first internal air flowing out from the second primary side outlet (63) of the second separation module (61) to the second primary side pipe (73) is supplied from the second primary side switching valve (76) to the second secondary. It flows out to the side pipe (74) and is discharged outside the shipping container (1). On the other hand, the second internal air flowing out from the second secondary outlet (64) of the second separation module (61) into the second secondary pipe (74) is converted into the second secondary switching valve (78). To the supply pipe (120) through the second secondary supply pipe (79).

  As described above, the supply pipe (120) includes the second outside air flowing out from the first separation module (41) (higher oxygen concentration than outside air: see FIG. 7), and the second separation module (61 ) Flowing out from the second chamber air (higher oxygen concentration than the chamber air: see FIG. 7) flows in. And the mixed air (mixed air whose oxygen concentration is higher than the atmosphere) of the second outside air and the second inside air flowing through the supply pipe (120) is the secondary flow path (29b) of the container refrigerator (10). ) And is supplied to the cargo compartment (5) together with the air flowing through the secondary flow path (29b).

  At this time, a part of the air in the warehouse passes through the ventilation exhaust pipe (100) and is discharged to the outside of the transport container (1).

  As described above, in the oxygen concentration recovery operation, the second outside air having a higher oxygen concentration than the atmosphere is supplied, and at the same time, the inside air in the cargo compartment (5) is transported through the ventilation exhaust pipe (100). Drain outside (1) and restore the oxygen concentration in the air in the storage compartment (5) to an oxygen concentration equivalent to the atmosphere.

  The oxygen sensor (91) provided in the warehouse detects the oxygen concentration in the cargo compartment (5). When the oxygen concentration reaches the target concentration (oxygen concentration equivalent to the atmosphere), the oxygen concentration recovery operation is stopped. To do. Since the standard value for oxygen deficiency is set to less than 18% in the Industrial Safety and Health Law, the target concentration is not necessarily limited to 21% but may be set to 18% or more.

  The door of the container (1) may be configured to be locked until, for example, the oxygen concentration recovery operation is stopped. On the other hand, if the door is locked when the start switch is turned on at the start of the oxygen concentration recovery operation, it is possible to suppress erroneous operations such as accidentally opening the door during the oxygen concentration recovery operation.

-Effect of the embodiment-
According to this embodiment, for example, when the oxygen concentration recovery operation is performed before opening the door of the container (1), the mixed air (high oxygen) of the second outside air and the second inside air having a higher oxygen concentration than the atmosphere. Concentration gas) is supplied to the internal space having a low oxygen concentration. Therefore, the rate of increase of the oxygen concentration in the internal space of the container (1) is faster than when only air is ventilated and air is introduced into the internal space. In addition, when air with an oxygen concentration of about 21% is introduced into the internal space by simple ventilation, it takes a long time to replace almost all the air in the internal space with the air in order to return the internal space to an oxygen concentration equivalent to the air. In contrast, in this embodiment, by introducing a high oxygen concentration gas having a higher oxygen concentration than the atmosphere into the internal space, the time for returning the internal space to the oxygen concentration equivalent to the air can be shortened compared to the conventional case.

  Moreover, according to this embodiment, the 1st composition adjustment part (40) which isolate | separates nitrogen and oxygen from the external air of a storage (1), and produces | generates low oxygen concentration gas and high oxygen concentration gas, and storage High oxygen during recovery of oxygen concentration by the second composition control unit (60) that separates nitrogen, oxygen, and carbon dioxide from the air in the chamber (1) to generate low oxygen concentration gas and high oxygen concentration gas Since the concentration gas is supplied to the internal space of the storage (1), the time required for returning the internal space to the oxygen concentration equivalent to the atmosphere can be shortened compared to the conventional structure. ) Gas separation membrane (85), and the oxygen concentration can be recovered efficiently.

<< Embodiment 2 >>
The internal air conditioner (30) of Embodiment 2 will be described. The internal air conditioner (30) of the embodiment is obtained by changing the first composition adjusting unit (40) and the controller (110) in the internal air conditioner (30) of the first embodiment. The configuration of the composition adjustment unit (60) is the same as that of the first embodiment. Here, the point which is different from the air conditioner (30) in the first embodiment about the air conditioner (30) in the second embodiment will be described.

-Configuration of the first composition adjustment unit-
The 1st composition adjustment part (40) of this embodiment is the same as the 1st composition adjustment part (40) of Embodiment 1, and the outside air suck | inhaled from the exterior of the transport container (1) (unprocessed outside air) ) Is separated into first outside air and second outside air. The 1st composition adjustment part (40) of this embodiment is comprised so that unprocessed exterior air may be isolate | separated into 1st exterior air and 2nd exterior air by what is called PSA (Pressure Swing Adsorption) method. This is different from the first composition adjustment unit (40) of the first embodiment.

  As shown in FIG. 9, the first composition adjustment unit (40) of the present embodiment includes an air pump (231) instead of the first pump (36) of the pump unit (35). That is, in the internal air conditioner (30) of the present embodiment, the pump unit (35) includes the second pump (37) and the drive motor (38), but does not include the first pump (36). The first composition adjustment unit (40) of the present embodiment includes a first directional control valve (232) and a second directional control valve (233), a first adsorption cylinder (234), and a second adsorption cylinder (235). With. As will be described later, each adsorption cylinder (234, 235) is provided with an adsorbent that adsorbs nitrogen in the air.

<air pump>
The air pump (231) is disposed in the internal space of the unit case (32). The air pump (231) includes a first pump mechanism (231a) and a second pump mechanism (231b) that each sucks, pressurizes, and discharges air. The first pump mechanism (231a) and the second pump mechanism (231b) are oilless pumps that do not use lubricating oil. Both the first pump mechanism (231a) as the pressurizing unit and the second pump mechanism (231b) as the depressurizing unit are connected to the drive shaft of the drive motor (231c). Each of the first pump mechanism (231a) and the second pump mechanism (231b) is rotationally driven by a drive motor (231c), thereby sucking and pressurizing air from the suction port, and pressurizing air. Is discharged from the discharge port.

<Outside air pipe, discharge pipe, filter unit>
One end of an outside air pipe (241) that forms an outside air passage is connected to the suction port of the first pump mechanism (231a). The outer air pipe (241) is provided so as to penetrate the unit case (32). The other end of the external air pipe (241) located outside the unit case (32) is connected to the filter unit (220).

  The filter unit (220) includes an air filter (47). The air filter (47) is a filter for capturing dust or salt contained in the outside air. In the present embodiment, a membrane filter having air permeability and waterproofness is used as the air filter (47). The filter unit (220) is a member formed in a box shape, and introduces air (external air) that has passed through the air filter (47) into the external air pipe (241). Although not shown, the filter unit (220) is disposed on the downstream side of the condenser (13) in the external equipment room (28).

  One end of a discharge pipe (242) that forms a discharge passage is connected to the discharge port of the first pump mechanism (231a). The discharge pipe (242) is branched into two branch pipes at the other end, one branch pipe serving as the first directional control valve (232) and the other branch pipe serving as the second directional control valve (233). , Each connected.

<Suction tube, supply tube>
One end of a suction pipe (243) that forms a suction passage is connected to the suction port of the second pump mechanism (231b). The suction pipe (243) branches into two branch pipes on the other end side, one branch pipe serving as the first directional control valve (232) and the other branch pipe serving as the second directional control valve (233). , Each connected.

  One end of a supply connection pipe (244) that forms a supply passage is connected to the discharge port of the second pump mechanism (231b). The other end of the supply connection pipe (244) is connected to the supply pipe (120).

  The supply connection pipe (244) is provided with a check valve (264) and a supply-side on-off valve (273) in this order from one end to the other end. The check valve (264) only allows air to flow from one end to the other end of the supply connection pipe (244), and prevents backflow of air. The supply side opening / closing valve (273) is an opening / closing valve formed of an electromagnetic valve.

<Directional control valve>
Each of the first directional control valve (232) and the second directional control valve (233) is a switching valve having three ports. Each directional control valve (232, 233) has a first state in which the first port communicates with the second port and is blocked from the third port, and the first port communicates with the third port in the second state. It is configured to switch to the second state that is blocked from the other port.

  The first directional control valve (232) has a first port connected to one end of the first adsorption cylinder (234). In the first directional control valve (232), the branch pipe of the discharge pipe (242) is connected to the second port, and the branch pipe of the suction pipe (243) is connected to the third port. The first directional control valve (232) switches the first adsorption cylinder (234) between a state communicating with the first pump mechanism (231a) and a state communicating with the second pump mechanism (231b).

  The second port of the second direction control valve (233) is connected to one end of the second adsorption cylinder (235). In the second directional control valve (233), the branch pipe of the discharge pipe (242) is connected to the second port, and the branch pipe of the suction pipe (243) is connected to the third port. The second direction control valve (233) switches the second adsorption cylinder (235) between a state communicating with the first pump mechanism (231a) and a state communicating with the second pump mechanism (231b).

<Adsorption cylinder>
Each of the first adsorption cylinder (234) and the second adsorption cylinder (235) is a member provided with a cylindrical container closed at both ends and an adsorbent filled in the container.

  The adsorbent filled in these adsorption cylinders (234,235) has a property of adsorbing a nitrogen component in a pressurized state where the pressure is higher than atmospheric pressure and desorbing the nitrogen component in a reduced pressure state where the pressure is lower than atmospheric pressure. In the present embodiment, as the adsorbent, for example, a porous zeolite having pores having a pore diameter smaller than the molecular diameter of nitrogen molecules (3.0 angstroms) and larger than the molecular diameter of oxygen molecules (2.8 angstroms). Is used.

  In the first composition adjustment unit (40) of the present embodiment, the first adsorption cylinder (234) and the second adsorption cylinder (235) constitute the first separation unit (41). The two adsorption cylinders (234, 235) constituting the first separation unit (41) are configured to convert the untreated outside air into the first outside air having a higher nitrogen concentration and a lower oxygen concentration than the untreated outside air. It isolate | separates into 2nd outdoor air with a low nitrogen concentration and a high oxygen concentration compared with the air outside a processing chamber.

<Oxygen exhaust pipe>
The oxygen discharge pipe (245) forming the oxygen discharge passage is branched into two branch pipes on one end side, one branch pipe is at the other end of the first adsorption cylinder (234), and the other branch pipe is at the first. Two suction cylinders (235) are connected to each other. One check valve (261) is provided in each branch pipe of the oxygen discharge pipe (245). Each check valve (261) allows a flow of air flowing out from the corresponding adsorption cylinder (234, 235) and blocks a flow of reverse air.

  The oxygen discharge pipe (245) is provided so as to penetrate the unit case (32). The other end of the oxygen discharge pipe (245) opens to the outside space of the transport container (1). A check valve (262) and an orifice (263) are provided at the assembly portion of the oxygen discharge pipe (245). The check valve (262) is disposed closer to the other end of the oxygen exhaust pipe (245) than the orifice (263). The check valve (262) allows the air flow toward the other end of the oxygen discharge pipe (245) and blocks the reverse air flow.

<Purge pipe>
A purge pipe (250) that forms a purge passage is connected to each branch pipe of the oxygen discharge pipe (245). One end of the purge pipe (250) is connected to the branch pipe connected to the first adsorption cylinder (234), and the other end is connected to the branch pipe connected to the second adsorption cylinder (235). One end of the purge pipe (250) is connected between the first adsorption cylinder (234) and the check valve (261). The other end of the purge pipe (250) is connected between the second adsorption cylinder (235) and the check valve (261).

  The purge pipe (250) is provided with a purge valve (251). The purge valve (251) is an open / close valve composed of an electromagnetic valve. The purge valve (251) is opened when pressure-equalizing the first adsorption cylinder (234) and the second adsorption cylinder (235). Further, one orifice (252) is provided on each side of the purge valve (251) in the purge pipe (250).

<Exhaust connection pipe>
An exhaust connection pipe (271) that forms an exhaust connection passage is connected to the supply connection pipe (244). The exhaust connection pipe (271) has one end connected to the supply connection pipe (244) and the other end connected to the oxygen discharge pipe (245). One end of the exhaust connection pipe (271) is connected between the second pump mechanism (231b) and the check valve (264) in the supply connection pipe (244). The other end of the exhaust connection pipe (271) is connected to the outer side of the check valve (262) of the oxygen discharge pipe (245).

  The exhaust connection pipe (271) is provided with an exhaust on-off valve (272). The exhaust on-off valve (272) is an on-off valve composed of an electromagnetic valve. The exhaust on-off valve (272) is opened when the air flowing through the supply connecting pipe (244) is discharged out of the warehouse.

<Measurement connection tube>
A measurement connection pipe (281) that forms a measurement passage is connected to the supply connection pipe (244). The measurement connecting pipe (281) is a pipe for connecting the first composition adjusting unit (40) to the sensor unit (90).

  The measurement connection pipe (281) has one end connected to the supply connection pipe (244) and the other end connected to the measurement pipe (125). One end of the measurement connection pipe (281) is connected between the check valve (264) and the supply-side on-off valve (273) in the supply connection pipe (244). The other end of the measurement connection pipe (281) is connected between the measurement on-off valve (126) and the sensor unit (90) in the measurement pipe (125).

  The measurement connection pipe (281) is provided with a measurement on-off valve (282). The measurement on-off valve (282) is an on-off valve composed of an electromagnetic valve. The measurement on-off valve (282) is opened when air flowing through the supply connecting pipe (244) is sent to the sensor unit (90).

<Bypass pipe>
A bypass connection pipe (255) that forms a bypass passage is connected to the discharge pipe (242). The bypass connection pipe (255) has one end connected to the discharge pipe (242) and the other end connected to the measurement connection pipe (281). One end of the bypass connection pipe (255) is connected closer to the first pump mechanism (231a) than the branch point of the discharge pipe (242). The other end of the bypass connection pipe (255) is connected between one end of the measurement connection pipe (281) and the measurement on-off valve (282). The bypass connection pipe (255) is a first bypass for bypassing the first adsorption cylinder (234) and the second adsorption cylinder (235) to supply outside air to the interior space of the transport container (1). Form a passage.

  A bypass opening / closing valve (256) is provided in the bypass connection pipe (255). The bypass on-off valve (256) is an on-off valve composed of an electromagnetic valve. The bypass on-off valve (256) constitutes a first bypass valve mechanism for changing the flow rate of outside air flowing into the bypass connection pipe (255). This bypass on-off valve (256) is opened when the outside air discharged by the first pump mechanism (231a) is supplied to the cargo compartment (5) without changing its composition.

-Operation of the first composition adjustment unit-
The operation of the first composition adjustment unit (40) of this embodiment will be described.

  The first composition adjustment unit (40) of the present embodiment alternately performs unprocessed outside air by repeating a first operation and a second operation described later alternately for a predetermined time (for example, 14.5 seconds). It separates into 1 outside air and 2nd outside air. Moreover, the 1st composition adjustment part (40) of this embodiment is the same as the 1st composition adjustment part (40) of Embodiment 1, and the oxygen concentration reduction operation | movement of a chamber air conditioner (30) and a carbon dioxide concentration reduction are carried out. In each of the operations, an operation of separating the unprocessed outside air into the first outside air and the second outside air is performed.

<First operation>
As shown in FIG. 10, in the first operation, the first directional control valve (232) is set to the first state, and the second directional control valve (233) is set to the second state. As a result, the discharge port of the first pump mechanism (231a) is connected to the first suction cylinder (234), and the second suction cylinder (235) is connected to the suction port of the second pump mechanism (231b). In the first operation, the supply-side on-off valve (273) is opened and the remaining on-off valves (251, 256, 272, 282) are closed. In the first operation, an adsorption operation for the first adsorption cylinder (234) and a desorption operation for the second adsorption cylinder (235) are performed.

  The first pump mechanism (231a) sucks and pressurizes unprocessed outside air from the outside air pipe (241), and supplies the pressurized unprocessed outside air to the first adsorption cylinder (234). In the first adsorption cylinder (234), nitrogen contained in the supplied unprocessed outside air is adsorbed by the adsorbent. As a result, in the first adsorption cylinder (234), second outdoor air having a lower nitrogen concentration and a higher oxygen concentration than untreated outdoor air is generated. The second outside air flows out from the first adsorption cylinder (234), flows through the oxygen discharge pipe (245), and is discharged to the outside space as discharge air.

  On the other hand, the second pump mechanism (231b) sucks air from the second adsorption cylinder (235). In the second adsorption cylinder (235), the pressure inside the cylinder decreases and nitrogen is desorbed from the adsorbent. As a result, in the second adsorption cylinder (235), the first outside air having a higher nitrogen concentration and a lower oxygen concentration than the untreated outside air is generated. The first outside air flows from the first adsorption cylinder (234) into the suction pipe (243) and is sucked into the second pump mechanism (231b). The second pump mechanism (231b) pressurizes the sucked first outside air and discharges it to the supply connecting pipe (244). The first outside air flows through the supply connecting pipe (244) as supply air, and is supplied to the internal space after joining the air flowing through the supply pipe (120).

<Second operation>
As shown in FIG. 11, in the second operation, the first directional control valve (232) is set to the second state, and the second directional control valve (233) is set to the first state. As a result, the discharge port of the first pump mechanism (231a) is connected to the second suction cylinder (235), and the first suction cylinder (234) is connected to the suction port of the second pump mechanism (231b). In the second operation, the supply-side on-off valve (273) is opened and the remaining on-off valves (251, 256, 272, 282) are closed. In the second operation, the desorption operation targeting the first adsorption cylinder (234) and the adsorption operation targeting the second adsorption cylinder (235) are performed.

  The first pump mechanism (231a) sucks and pressurizes the untreated outside air from the outside air pipe (241), and supplies the pressurized untreated outside air to the second adsorption cylinder (235). In the second adsorption cylinder (235), nitrogen contained in the supplied unprocessed outside air is adsorbed by the adsorbent. As a result, in the second adsorption cylinder (235), second outside air having a lower nitrogen concentration and a higher oxygen concentration than untreated outside air is generated. The second outside air flows out from the second adsorption cylinder (235), flows through the oxygen discharge pipe (245), and is discharged to the outside space as discharge air.

  On the other hand, the second pump mechanism (231b) sucks air from the first adsorption cylinder (234). In the first adsorption cylinder (234), the internal pressure is reduced and nitrogen is desorbed from the adsorbent. As a result, in the first adsorption cylinder (234), the first outside air having a higher nitrogen concentration and a lower oxygen concentration than the untreated outside air is generated. The first outside air flows from the first adsorption cylinder (234) into the suction pipe (243) and is sucked into the second pump mechanism (231b). The second pump mechanism (231b) pressurizes the sucked first outside air and discharges it to the supply connecting pipe (244). The first outside air flows through the supply connecting pipe (244) as supply air, and is supplied to the internal space after joining the air flowing through the supply pipe (120).

<Oxygen concentration recovery operation>
In the second embodiment, the oxygen concentration recovery operation is performed by the second composition adjustment unit (60). At this time, in the supply pipe (120), the second internal air (air having a higher oxygen concentration than the internal air) flowing out from the second separation module (61) is supplied to the second secondary pipe and the second secondary pipe. Inflow from the side supply pipe (79). The second outside air flowing through the supply pipe (120) flows into the secondary flow path (29b) of the container refrigerator (10), and enters the cargo compartment (5) together with the air flowing through the secondary flow path (29b). Supplied. A part of the air in the cabinet is discharged outside the transport container (1) through the ventilation exhaust pipe (100).

  In this way, in the oxygen concentration recovery operation, the air in the second compartment with high oxygen concentration is supplied to the cargo compartment (5), and at the same time, the air in the cargo compartment (5) is transported through the ventilation exhaust pipe (100). It is discharged outside the container (1), and the oxygen concentration in the air in the cargo compartment (5) is restored to the oxygen concentration equivalent to the atmosphere.

  The oxygen concentration in the cargo compartment (5) is detected by the oxygen sensor (91) provided in the warehouse, and when the oxygen concentration reaches the target concentration (oxygen concentration equivalent to the atmosphere), the oxygen concentration recovery operation is stopped.

<< Other Embodiments >>
The following modifications may be applied to the internal air conditioner (30) of the above embodiments. Note that the following modifications may be combined or replaced as appropriate as long as the function of the internal air conditioner (30) is not impaired.

-First modification-
In the oxygen concentration recovery operation of the first embodiment, in the oxygen concentration reduction operation, the first primary side switching valve (56), the first secondary side switching valve (58), the second primary side switching valve (76), and the first Although the example in which the oxygen concentration recovery operation (first oxygen concentration recovery operation) in FIG. 7 is performed by setting all of the second secondary side switching valves (78) to the second state has been described, The first primary side switching valve (56), the first secondary side switching valve (58), the second primary side switching valve (76), and the second secondary side switching valve (78) are all set to the second state. Thus, the oxygen concentration recovery operation (second oxygen concentration recovery operation) shown in FIG. 8 can be performed.

  In the first embodiment, the second pump (37) is operated in both the first oxygen concentration recovery operation shown in FIG. 7 and the second oxygen concentration recovery operation shown in FIG. The air in the second chamber with a high oxygen concentration is returned to the container (1). In this example, the oxygen concentration in the second chamber is higher than the air in the chamber but lower than the atmosphere. The second pump (37) is operated halfway (for example, until the oxygen concentration in the interior space reaches 18%), and thereafter the oxygen recovery operation is performed only by the first pump, or the second pump (37) from the beginning. It is also possible to perform the oxygen recovery operation only with the first pump (36). However, since the standard value for oxygen deficiency is set to less than 18% in the Industrial Safety and Health Law, both the second outside air and the second inside air that meet this standard are required from the start to the end of the oxygen concentration recovery operation. There is no problem in use, and the oxygen concentration recovery time can be shortened compared to when the second pump (37) is stopped halfway.

  Further, in both cases of the first oxygen concentration recovery operation and the second oxygen concentration recovery operation of the first embodiment, at least the second outside air of the second outside air and the second inside air is supplied to the container ( Ventilation may be carried out at the same time as supplying to the inside of 1), and the inside space may be brought close to the oxygen concentration equivalent to the atmosphere. In this way, ventilation is performed at the same time when the oxygen concentration recovery operation is performed, and the atmosphere is mixed with a part of the air supplied to the internal space, so that all the gas is generated by the gas composition adjustment unit (40, 60). Energy saving can be achieved compared to the case.

  The oxygen concentration of the high oxygen concentration gas used for the oxygen concentration recovery operation in the first embodiment and the first modification is an example, and the opening degree of the first control valve (46) and the second control valve (66). By adjusting the pressure, the separation performance can be adjusted by adjusting the pressure of outside air and inside air passing through the gas separation membrane (85), so for example, high oxygen concentration gas with higher oxygen concentration is generated and supplied to the inside space Then, the operation time of the oxygen concentration recovery operation may be further shortened.

-Second modification-
In the internal air conditioner (30) of Embodiment 1, the gas separation membrane (85) of the first separation module (41) and the gas separation membrane (85) of the second separation module (61) have mutually different characteristics. May be different.

-Third modification-
In the internal air conditioner (30) of the first embodiment, the first bypass valve (50) flows into the first bypass pipe (51) and the flow rate of the unprocessed outside air flowing into the first separation module (41). You may be comprised so that the ratio of the flow volume of the unprocessed exterior air to perform can be changed in multiple steps or continuously. In addition, the second bypass valve (70) determines the ratio of the flow rate of the untreated storage air flowing into the second separation module (61) and the flow rate of the unprocessed storage air flowing into the second bypass pipe (71). , It may be configured to be changed in multiple stages or continuously.

-Fourth modification-
In the internal air conditioner (30) of Embodiment 1, a drive motor may be connected to each of the first pump (36) and the second pump (37). In this modification, it becomes possible to operate one of the first pump (36) and the second pump (37) and to pause the other.

-5th modification-
In the internal air conditioner (30) of Embodiment 1, each of the first composition adjustment unit (40) and the second composition adjustment unit (60) mutually absorbs the sucked air by a so-called PSA (Pressure Swing Adsorption) method. You may be comprised so that it may isolate | separate into two types of air from which a composition differs. Embodiment 2 is an example in which the configuration of the PSA method is used for the second composition adjustment unit (60), but the PSA method is used for each of the first composition adjustment unit (40) and the second composition adjustment unit (60). In the configuration, the composition adjustment unit (40, 60) generates an air having a low nitrogen concentration and a high oxygen concentration and carbon dioxide concentration by adsorbing nitrogen contained in the sucked air to the adsorbent, The process of desorbing nitrogen from the agent to generate air having a high nitrogen concentration and a low oxygen concentration and low carbon dioxide concentration is alternately repeated.

-Sixth Modification-
The internal air conditioner (30) of each of the above embodiments may be provided in a stationary refrigerator or freezer. The internal air conditioner (30) of each of the above embodiments may be provided in a refrigerated / frozen container for land transportation that is transported by truck, rail, or the like. Further, the internal air conditioner (30) of each of the above embodiments may be provided in a refrigeration / freezing truck in which a box that forms a cargo compartment is integrated with a chassis.

  While the embodiments and the modifications have been described above, various changes in form and details can be made without departing from the spirit and scope of the claims. In addition, the above embodiments and modifications may be appropriately combined or replaced as long as the functions of the subject of the present disclosure are not impaired.

  As described above, the present disclosure is useful for an internal air conditioner that adjusts the composition of internal air in a storage.

1 Transport container (storage)
30 Internal air conditioner
40 1st composition adjustment part (gas composition adjustment part)
53 First primary pipe (gas passage)
54 First secondary pipe (gas passage)
55 External suction pipe (gas passage)
60 Second composition adjustment unit (gas composition adjustment unit)
73 Second primary pipe (gas passage)
74 Second secondary pipe (gas passage)
75 Inside suction pipe (gas passage)
85 Gas separation membrane
100 Exhaust pipe for ventilation (ventilation passage)
110 Controller
111 CPU (oxygen concentration recovery control unit)
120 Supply pipe (gas passage)

Claims (5)

An internal air conditioner that adjusts the composition of the internal air in the storage (1),
A gas composition control unit (40, 60) capable of generating a low oxygen concentration gas having a lower oxygen concentration than the atmosphere and a high oxygen concentration gas having a higher oxygen concentration than the atmosphere;
Gas passages (53 to 55, 73 to 75, 120) communicating with the internal space and external space of the gas composition adjusting section (40, 60) and the storage (1);
The low oxygen oxygen gas generated by the gas composition adjusting unit (40, 60) is supplied to the internal space through the gas passage (53, 55, 73, 75, 120) and the high oxygen concentration gas is supplied to the gas passage ( 54, 55, 74, 75), and a controller (110) for performing an oxygen concentration reduction operation for discharging to the external space and reducing the oxygen concentration of the internal space,
The controller (110) supplies the high oxygen concentration gas generated by the gas composition adjusting unit (40, 60) to the internal space, and returns the oxygen concentration in the internal space to a concentration corresponding to the atmosphere. An internal air conditioner comprising an oxygen concentration recovery control unit (111) for performing recovery operation. In claim 1,
It has a ventilation passage (100) that communicates with the internal space and external space of the storage (1).
The controller (110) performs the ventilation of the internal space simultaneously with the ventilation passage (100) when performing the oxygen concentration recovery operation. In claim 1 or 2,
The gas composition adjusting unit (40, 60) separates nitrogen and oxygen from the outside air of the storage (1), a low oxygen concentration gas having a higher nitrogen concentration and a lower oxygen concentration than the atmosphere, and the atmosphere A high oxygen concentration gas having a lower nitrogen concentration and a higher oxygen concentration, and a first composition adjustment unit (40) for generating by a gas separation membrane (85),
The controller (110) supplies the high oxygen concentration gas generated by the first composition adjustment unit (40) to the internal space when performing the oxygen concentration recovery operation. apparatus. In claim 3,
The gas composition adjusting unit (40, 60) separates nitrogen, oxygen and carbon dioxide from the air in the storage (1), and the nitrogen concentration is higher than the air in the storage, and the oxygen concentration and the carbon dioxide concentration. The second composition adjustment unit (60) that generates a low oxygen concentration gas having a low oxygen concentration and a high oxygen concentration gas having a lower nitrogen concentration and a higher oxygen concentration and carbon dioxide concentration than the air in the cabinet by a gas separation membrane (85) And
The controller (110) supplies the high oxygen concentration gas generated by the second composition adjustment unit (60) to the internal space when performing the oxygen concentration recovery operation. apparatus. In claim 4,
Instead of the first composition adjustment unit (40), nitrogen, oxygen and carbon dioxide are separated from the air in the storage (1), and the nitrogen concentration is higher than the air in the storage, and the oxygen concentration and the carbon dioxide concentration. Is equipped with an adsorbing part (234,235) provided with an adsorbent capable of generating a low oxygen concentration gas having a low nitrogen concentration and a high oxygen concentration gas having a lower oxygen concentration and a higher carbon dioxide concentration than the inside air,
The controller (110) supplies the high oxygen concentration gas generated by the second composition adjustment unit (60) to the internal space when performing the oxygen concentration recovery operation. apparatus.

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