JP7185132B2 - Indoor air conditioner - Google Patents

Description

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

Conventionally, for the purpose of suppressing the deterioration of the freshness of plants such as agricultural products, the composition of the air inside the warehouse and the shipping container that stores agricultural products etc. (for example, the oxygen concentration and carbon dioxide concentration of the air inside the warehouse) is adjusted. Air conditioners are known.

Patent Document 1 discloses a container with a device for adjusting the composition of the air inside the container. The apparatus of Patent Literature 1 adjusts the composition of air in the refrigerator using a gas separation membrane having a higher permeability to carbon dioxide than to oxygen. Concretely, this apparatus contacts one surface of the gas separation membrane with the air in the warehouse containing carbon dioxide, and the other surface of the gas separation membrane with the outside air containing almost no carbon dioxide, thereby separating agricultural products, etc. Carbon dioxide produced by respiration is discharged to the outside of the container (see page 20, line 14 to page 21, line 2 of the specification of Patent Document 1).

In a container equipped with this type of device, in order to keep plants such as agricultural products fresh for a long period of time, the air inside the warehouse generally has an oxygen concentration (for example, 5 to 8%) lower than that of the atmosphere (approximately 21%). maintained. In addition, when taking out cargo such as agricultural products transported or stored in a container, before opening the container door, ventilate to return the oxygen concentration of the air inside the container to that of the atmosphere, and keep the oxygen concentration low. A process is being performed that does not open the inside of the refrigerator.

WO2007/033668

However, even if air with an oxygen concentration of about 21% is introduced by ventilation into the internal space of the container where the oxygen concentration is low, the oxygen concentration of the air inside the container immediately becomes about 21%, which is equivalent to the atmosphere. It takes a long time to replace almost all of the air in the refrigerator with the atmosphere.

The present disclosure has been made in view of such problems, and its purpose is to shorten the time to return the air inside a storage container such as a container maintained at a low oxygen concentration to the atmosphere equivalent. .

A first aspect of the present disclosure presupposes an indoor air conditioner for adjusting the composition of indoor air inside a storage (1).

The indoor air conditioner includes gas composition control units (40, 60) capable of generating a low-oxygen concentration gas having an oxygen concentration lower than that of the atmosphere and a high-oxygen concentration gas having an oxygen concentration higher than that of the atmosphere; Gas passages (53 to 55, 73 to 75, 120) communicating with the composition control unit (40, 60) and the internal and external spaces of the storage (1), and the gas composition control unit (40, 60) The generated low-oxygen oxygen gas is supplied to the internal space through the gas passages (53, 55, 73, 75, 120), and the high-oxygen concentration gas is supplied to the external space through the gas passages (54, 55, 74, 75). a controller (110) that performs an oxygen concentration reduction operation that discharges the gas into the space to reduce the oxygen concentration in the internal space, wherein the controller (110) is generated by the gas composition adjustment section (40, 60) and an oxygen concentration recovery control unit (111) for performing an oxygen concentration recovery operation for supplying the high oxygen concentration gas thus obtained to the internal space and returning the oxygen concentration in the internal space to a concentration corresponding to the atmosphere. do.

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, the high oxygen concentration gas having a higher oxygen concentration than the atmosphere flows into the inner space having a low oxygen concentration. supplied. Therefore, the oxygen concentration in the internal space rises faster than when only ventilation is performed and the atmosphere is introduced into the internal space.

A second aspect is the first aspect, provided with a ventilation passageway (100) that communicates with the interior space and the exterior space of the storage (1), and the controller (110) performs the oxygen concentration recovery operation. Sometimes, the internal space is simultaneously ventilated by the ventilation passage (100).

In this second aspect, for example, if the oxygen concentration recovery operation is performed before opening the door of the storage (1) such as a container, the high oxygen concentration gas having a higher oxygen concentration than the atmosphere flows into the inner space having a low oxygen concentration. At the same time, air is introduced into the inner space by ventilation.

In a third aspect, in the first or second aspect, the gas composition adjusting section (40, 60) separates nitrogen and oxygen from the outside air of the storage (1), A first composition control section (40) for generating a low oxygen concentration gas having a high concentration and a low oxygen concentration and a high oxygen concentration gas having a nitrogen concentration lower than that of the atmosphere and a high oxygen concentration by a gas separation membrane (85). wherein the controller (110) supplies the high oxygen concentration gas generated in the first composition control section (40) to the internal space when performing the oxygen concentration recovery operation.

In this third aspect, the oxygen concentration recovery is performed by the first composition control 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. A high oxygen concentration gas is supplied to the internal space of the storage (1) during operation.

In a fourth aspect based on the third aspect, the gas composition adjusting section (40, 60) separates nitrogen, oxygen and carbon dioxide from the air inside the storage (1), and The gas separation membrane (85 ), wherein when the controller (110) performs the oxygen concentration recovery operation, the oxygen-rich gas generated in the second composition control unit (60) is supplied to the internal space.

In this fourth aspect, a first composition control 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, and a storage ( In combination with the second composition control unit (60) that separates nitrogen, oxygen and carbon dioxide from the air in the storage compartment to generate low oxygen concentration gas and high oxygen concentration gas, high oxygen concentration recovery operation is performed. Oxygen concentration gas is supplied to the internal space of the storage (1).

In a fifth aspect, in the fourth aspect, in place of the first composition adjusting section (40), nitrogen, oxygen and carbon dioxide are separated from the inside air of the storage (1), and There is an adsorbent that can separate low-oxygen gas, which has a higher nitrogen concentration and lower oxygen and carbon dioxide concentrations, and high-oxygen gas, which has a lower nitrogen concentration and higher oxygen and carbon dioxide concentrations than the air inside the refrigerator. Adsorption sections (234, 235) are provided, and the controller (110) supplies the oxygen-rich gas generated in the second composition control section (60) to the internal space when the oxygen concentration recovery operation is performed. It is characterized by supplying

In this fifth aspect, the first composition control section ( 40), in addition to adsorption units (234, 235) provided with an adsorbent, the oxygen concentration recovery operation is performed using the second composition control unit (60) as in the fourth aspect.

According to the present disclosure, for example, when the oxygen concentration recovery operation is performed before opening the door of the storage (1) such as a container, the high oxygen concentration gas with a higher oxygen concentration than the atmosphere is supplied to the above internal space with a low oxygen concentration. be done. Therefore, the oxygen concentration in the internal space rises faster than when only ventilation is performed and the atmosphere is introduced into the internal space. In addition, if the atmosphere (oxygen concentration is about 21%) is introduced into the internal space only by simple ventilation, in order to return the internal space to the oxygen concentration equivalent to the atmosphere, it is necessary to replace almost all of the air in the internal space with the atmosphere. Although it takes time, according to the present disclosure, by introducing a high oxygen concentration gas having a higher oxygen concentration than the atmosphere into the interior space, the time to return the interior space to the oxygen concentration equivalent to the atmosphere is shortened. can.

According to the second aspect, for example, when the oxygen concentration recovery operation is performed before opening the door of the storage (1) such as a container, the high oxygen concentration gas having a higher oxygen concentration than the atmosphere Air is supplied to the space, and at the same time air is introduced into the inner space by ventilation. In this second mode, ventilation is also performed when the oxygen concentration recovery operation is performed, and by mixing air with the high oxygen concentration gas supplied to the internal space, all the high oxygen concentration gas generated in the gas composition adjustment unit (40, 60) Energy can be saved more than when oxygen concentration gas is used.

According to the third aspect, using the first composition control 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 By supplying high-oxygen-concentration gas to the internal space of storage (1) during the oxygen-concentration recovery operation, the time required to return the internal space to the oxygen concentration equivalent to the atmosphere can be shortened.

According to the fourth aspect, the first composition control unit (40) 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; Using a second composition control 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, during the oxygen concentration recovery operation By supplying the high-oxygen-concentration gas to the internal space of the storage (1), the time required to restore the oxygen concentration of the internal space to that of the atmosphere can be shortened.

According to the fifth aspect, the second composition control 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 exposed to the atmosphere. It is possible to shorten the time required to restore the oxygen concentration to a considerable level.

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

Embodiments will be described in detail based on 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 applications, or its uses.

<<Embodiment 1>>
The indoor air conditioner (30) of the present embodiment is provided in the transportation container (1) for so-called CA (Controlled Atmosphere) transportation. The indoor air conditioning device (30) adjusts the composition of the air inside the storage (internal space) inside the shipping container (1) so that it differs from the composition of the atmospheric air, which is the air in the external space. or adjust to return to the composition of

As shown in FIG. 1, a transport container (1) constituting a storage includes a container body (2) and a container refrigerator (10). This shipping container (1) is a reefer container with temperature control inside. The indoor air conditioner (30) of the present embodiment is installed in a container refrigerator (10). This transport container (1) is used to transport plants such as agricultural products that breathe by taking in oxygen (O ₂ ) in the air and releasing carbon dioxide (CO ₂ ) as cargo (6). Examples of plants include fruits such as bananas and avocados, vegetables, grains, bulbs, and fresh flowers.

The container main body (2) is formed in the shape of an elongated rectangular parallelepiped box. The container body (2) has one end face 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 luggage compartment (5) for storing cargo (6).

A floor plate (3) for loading cargo (6) is arranged at the bottom of the luggage compartment (5). Between the floor plate (3) and the bottom plate of the container body (2), an underfloor passage (4) is formed for flowing air blown out by the container refrigerator (10). 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 a space above the floor plate (3) (i.e., a space in which the cargo (6) is accommodated). ).

－Refrigerator for containers－
As shown in FIGS. 1 and 2, the container refrigerator (10) includes a casing (20), a refrigerant circuit (11) that performs a refrigerating cycle, an outside fan (16), and an inside 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 outside fan (16), and an inside fan (17).

The outer wall (21) is a plate-like member arranged to cover the open end of the container body (2). The outer wall portion (21) of the warehouse bulges out toward the inside of the container body (2) at its lower portion. The inner wall (22) is a plate-like member along the outer wall (21). The inner wall (22) is arranged to cover the outer wall (21) of the container body (2). A space between the outer wall (21) and the inner wall (22) is filled with a heat insulating material (23).

The casing (20) has a shape in which the lower part is recessed inside the container body (2). The lower part of the casing (20) forms an external equipment room (28) that communicates with the external space of the shipping container (1). An external fan (16) is arranged in the external equipment room (28).

The back plate (24) is a substantially rectangular plate-like member. The back plate (24) is arranged inside the container body (2) relative to the inner wall (22) and forms an inner air flow path (29) with the inner wall (22). The upper end of the internal air channel (29) forms the suction port (26) of the casing (20), and the lower end forms the outlet (27) of the casing (20).

The partition plate (25) is a plate-like member arranged to partition the internal air flow path (29) into upper and lower portions. The partition plate (25) is arranged above the internal air flow path (29). The partition plate (25) allows the internal air flow path (29) to be divided into a primary flow path (29a) above the division plate (25) and a secondary flow path (29b) below the division plate (25). is divided into The primary flow path (29a) communicates with the luggage compartment (5) through the suction port (26). The secondary channel (29b) communicates with the underfloor channel (4) through the 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. is a closed circuit. When the compressor (12) is operated, the refrigerant circulates through the refrigerant circuit (11) to perform a vapor compression refrigeration cycle. As shown in FIG. 1, the condenser (13) is arranged on the suction side of the outside fan (16) in the outside equipment room (28), and the evaporator (15) is located in the inside air flow path (29). is placed in the secondary flow path (29b) of the Although not shown in FIG. 1, the compressor (12) is arranged in the external equipment room (28).

－Inside air conditioner－
As shown in FIG. 1, the indoor air conditioner (30) includes a body unit (31), a sensor unit (90), a ventilation exhaust pipe (ventilation passage) (100), and 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 shipping container (1). The controller (110) is provided in the body unit (31) and controls the components of the indoor air conditioner (30). Details of the sensor unit (90), the ventilation exhaust pipe (100), and the controller (110) will be described later.

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

The indoor air conditioner (30) also 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 for connecting the main unit (31) to the internal air flow path (29) of the container refrigerator (10). Plumbing.

The supply pipe (120) is a pipe for supplying the air flowing out from the first composition control section (40) and the second composition control section (60) to the luggage compartment (5). The supply pipe (120) has an inlet end connected to the first composition adjusting section (40) and the second composition adjusting section (60), and an outlet end connected to the 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 luggage compartment (5) to the second composition control section (60). The inlet end of the inside suction pipe (75) opens into the secondary flow path (29b) of the inside air flow path (29), and the outlet end of the inside suction pipe (75) connects to a second pump ( 37). In the secondary flow path (29b) of the internal air flow path (29), the inlet end of the inside suction pipe (75) is arranged upstream of the outlet end of the supply pipe (120).

The measurement pipe (125) is a pipe for supplying air flowing through the supply pipe (120) to the sensor unit (90). The measuring pipe (125) is connected at its inlet end to the supply pipe (120) and at its outlet end to the sensor unit (90). In addition, the measurement pipe (125) is provided with a measurement on-off valve (126) comprising an electromagnetic valve. The measurement on-off valve (126) is housed in the unit case (32) of the body unit (31).

In addition, the ventilation exhaust pipe (100), the supply pipe (120), the inside suction pipe (75), the measurement pipe (125), and each composition adjustment part (40, 60) described later. Piping (51-55, 57, 59, 71-74, 77, 79, 98) may consist of rigid pipes, flexible hoses, or pipes and hoses may be configured by combining Each of the above pipes (53-55, 73-75, 120) is a pipe that constitutes the gas passage of the present disclosure.

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

<First composition control unit>
The first composition control unit (40) separates the outside air (untreated outside air) sucked from the outside of the shipping container (1) into the first outside air (low-oxygen concentration gas) and the second outside air (low oxygen concentration gas). oxygen-rich gas). The first composition adjusting section (40) of the present embodiment supplies the first outside air, which is supply air, to the luggage compartment (5), and discharges the second outside air to the outside of the shipping container (1). do.

The first composition control section (40) includes an air filter (47), a first separation module (41), a first bypass valve (50), a first pressure sensor (45) and a first control valve (46). and The first composition adjusting 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). The first pump (36) of the pump unit (35) constitutes the first composition adjusting section (40).

The air filter (47) is a membrane filter for capturing dust, salt, and the like contained in 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) through the outside suction pipe (55). In addition, in the indoor air conditioning device (30) of the present embodiment, the outside suction pipe (55) is omitted, and the air filter (47) and the first air filter (47) are supplied through the internal space of the unit case (32), which is a sealed container. A pump (36) may be communicated.

The first separation module (41) includes a first inlet (42), a first primary outlet (43), and a first secondary outlet (44), which will be described in detail later. The first inlet (42) is connected to the discharge port of the first pump (36) through the first inlet pipe (52). The first primary outlet (43) is connected to the supply pipe (120) via the first primary pipe (53). One end of a first secondary pipe (54) is connected to the first secondary outlet (44). The first secondary side 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 outside fan (16) in the outside 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 a first state in which the first port communicates with the second port. 3 and is switched to a second state (a state indicated by a dashed line in FIG. 3) in which communication with the port No. 3 is interrupted from the second port.

The first bypass valve (50) is arranged in the middle of the first introduction pipe (52). A first bypass valve (50) has a first port connected to the outlet of the first pump (36) and a second port connected to the first inlet (42) of the first separation module (41). . The inlet end 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) connects to the first primary side 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 arranged closer to the first separation module (41) than the other end of the first bypass pipe (51) connected to the first primary side pipe (53). placed. Also, the first pressure sensor (45) is arranged 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 first pressure sensor (45) reading is substantially equal to the pressure of the untreated outside air supplied by the first pump (36) to the first separation module (41).

The first control valve (46) is an electrically operated valve with a variable opening, and constitutes a first valve mechanism. Changing the degree of opening of the first control valve (46) changes the pressure of the untreated outside air supplied by the first pump (36) to the first separation module (41).

The first separation module (41) constitutes a first separation section. Although details will be described later, the first separation module (41) includes a gas separation membrane (85). The first separation module (41) divides the untreated outside air into the first outside air that has not permeated the gas separation membrane (85) (the air flowing through the first primary side pipe (53)), the gas The second outside air (air flowing through the first secondary side pipe (54)) permeated through the separation membrane (85) is separated.

The first outside air has a higher nitrogen concentration than the untreated outside air and a lower oxygen concentration than the untreated outside 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. In this way, the first outside air and the second outside air differ from each other in the concentrations of the substances that constitute them. In addition, the density|concentration in this specification means a volume ratio.

The first composition control section (40) includes a first primary side switching valve (56), a first primary side discharge pipe (57), a first secondary side switching valve (58), a first 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 (Fig. 3) and a second state (state shown by broken lines in FIG. 3) in which the first port communicates with the third port and is blocked from the second port (state shown by broken lines in FIG. 3). be.

The first primary side switching valve (56) is arranged in the middle of the first primary side pipe (53). In the first primary side pipe (53), the first primary side switching valve (56) is arranged 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 side discharge pipe (57) is connected to the first secondary side pipe (54).

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

<Second composition control section>
The second composition control section (60) divides the internal air (untreated internal air) sucked from the internal space of the shipping container (1) into the first internal air (low-oxygen concentration gas) and the second internal air. (oxygen-rich gas). The second composition control section (60) of the present embodiment supplies the first internal air to the luggage compartment (5), and discharges the second internal air, which is discharge air, to the outside of the shipping container (1). do.

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

The second separation module (61) includes a second inlet (62), a second primary outlet (63), and a second secondary outlet (64), which will be described in detail later. The second inlet (62) is connected to the discharge port of the second pump (37) through the second inlet pipe (72). The second primary outlet (63) is connected to the supply pipe (120) through the second primary pipe (73). One end of a second secondary pipe (74) is connected to the second secondary outlet (64). The second secondary side 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 outside fan (16) in the outside 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 (a state indicated by a solid line in FIG. 3), and a state in which the first port communicates with the second port. 3 and is switched to a second state (a state indicated by a dashed line in FIG. 3) in which communication with the port No. 3 is interrupted from the second port.

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

A second pressure sensor (65) and a second control valve (66) are provided in the second primary side pipe (73). The second pressure sensor (65) and the second control valve (66) are arranged closer to the second separation module (61) than the other end of the second bypass pipe (71) connected to the second primary side pipe (73). placed. Also, the second pressure sensor (65) is arranged 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 outlet (63) of the second separation module (61). The second pressure sensor (65) reading is substantially equal to the pressure of the untreated warehouse air supplied by the second pump (37) to the second separation module (61).

The second control valve (66) is an electrically operated valve with a variable opening, and constitutes a second valve mechanism. Changing the degree of opening of the second control valve (66) changes the pressure of the untreated internal air supplied by the second pump (37) to the second separation module (61).

The second separation module (61) constitutes a second separation section. Although details will be described later, the second separation module (61) includes a gas separation membrane (85). The second separation module (61) divides the untreated internal air into the first internal air that has not permeated the gas separation membrane (85) (the air flowing through the second primary side pipe (73)) and the gas It is separated into the second internal air (air flowing through the second secondary side pipe (74)) that has permeated the separation membrane (85).

The first inside air has a nitrogen concentration higher than that of the untreated inside air, and an oxygen concentration and a carbon dioxide concentration lower than those of the untreated inside air. The second inside air has a lower nitrogen concentration than the untreated inside air, and higher oxygen and carbon dioxide concentrations than the untreated inside air. In this way, the first and second compartment airs differ from each other in the concentration of substances that constitute them.

The second composition control section (60) includes a second primary side switching valve (76), a second primary side discharge pipe (77), a second secondary side switching valve (78), a second 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 (Fig. 3) and a second state (state shown by broken lines in FIG. 3) in which the first port communicates with the third port and is blocked from the second port (state shown by broken lines in FIG. 3). be.

The second primary side switching valve (76) is arranged in the middle of the second primary side pipe (73). In the second primary pipe (73), the second primary switching valve (76) is arranged closer to the supply pipe (120) than the outlet end of the second bypass pipe (71). The second primary 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 arranged 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 arranged 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 a second port connected to the second secondary pipe. (74) communicates with the external equipment room (28) of the shipping container (1). A third port of the second secondary switching valve (78) is connected to one end of a second secondary supply pipe (79). The other end of the second secondary side 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) are described with reference to FIG. The structures of the first separation module (41) and the second separation module (61) are the same.

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

Each separation module (41, 61) has a large number of gas separation membranes (85) formed in the shape of hollow fibers (that is, in the shape of very thin tubes with an outer diameter of 1 mm or less). The hollow fiber gas separation membrane (85) is provided from one partition wall (81a) to the other partition wall (81b). Each gas separation membrane (85) has one end penetrating one partition wall (81a) to open into the introduction chamber (82), and the other end penetrating the other partition wall (81b) to lead out to the primary side. It opens into the chamber (83). In the inner space of the tubular case (80), the portion of the space sandwiched between the two partition walls (81a, 81b) outside the gas separation membrane (85) constitutes the secondary outlet chamber (84). . In each separation module (41, 61), the inlet chamber (82) and the primary outlet chamber (83) communicate with each other through a hollow fiber gas separation membrane (85), while the secondary outlet chamber (84) , the space inside the gas separation membrane (85), the inlet chamber (82), and the primary outlet chamber (83).

The cylindrical case (80) is provided with inlets (42, 62), primary outlets (43, 63), and secondary outlets (44, 64). The introduction port (42, 62) is arranged at the left end of the cylindrical case (80) in FIG. 4 and communicates with the introduction chamber (82). The primary outlet (43, 63) is arranged at the right end of the tubular case (80) in FIG. 4 and communicates with the primary outlet chamber (83). The secondary outlet (44, 64) is arranged in the longitudinally intermediate portion of the cylindrical case (80) and communicates with the secondary outlet chamber (84).

The gas separation membrane (85) is a non-porous membrane made of polymer. The gas separation membrane (85) separates the components contained in the mixed gas by utilizing the fact that molecules permeate the gas separation membrane (85) at different speeds (permeation speeds) for different substances.

In the indoor air conditioner (30) of the present 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 the property that the nitrogen permeation rate is lower than both the oxygen permeation rate and the carbon dioxide permeation rate. The multiple hollow fiber gas separation membranes (85) have substantially the same thickness. Therefore, the gas separation membrane (85) provided in each separation module (41, 61) has a characteristic that the nitrogen permeability is lower than both the oxygen permeability and the carbon dioxide permeability.

In each separation module (41, 61), the air that has flowed into the introduction chamber (82) through the inlet (42, 62) flows through the space inside the hollow fiber gas separation membrane (85) into the primary side outlet chamber ( 83). Some of the air flowing through the space inside the gas separation membrane (85) permeates the gas separation membrane (85) and moves to the secondary outlet chamber (84), and the rest is in the primary outlet chamber (83). flow into

The gas separation membrane (85) of each separation module (41, 61) has a lower permeability to nitrogen than to oxygen and carbon dioxide. That is, nitrogen is less permeable through the gas separation membrane (85) than oxygen and carbon dioxide. Therefore, as the air flowing inside the hollow fiber gas separation membrane (85) approaches the primary side outlet chamber (83), the nitrogen concentration increases and the oxygen and carbon dioxide concentrations decrease. Oxygen and carbon dioxide contained in the air flowing through the hollow fiber gas separation membrane (85) pass through the gas separation membrane (85) and move to the secondary outlet chamber (84).

As a result, the air that has flowed into the primary outlet chamber (83) without permeating the gas separation membrane (85) has a higher nitrogen concentration than the air in the inlet chamber (82). is lower than the air in the introduction chamber (82). In addition, 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 inlet chamber (82), and has an oxygen concentration and a carbon dioxide concentration of higher than the air in the introduction chamber (82).

In the first separation module (41), the untreated outside air flows into the introduction chamber (82) from the first inlet (42) and passes through the primary side outlet chamber (83) without passing through the gas separation membrane (85). The air that has flowed into the first compartment flows out of the first primary side outlet (43) as air outside the first compartment, permeates the gas separation membrane (85), and flows into the secondary side 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 untreated internal air flows from the second inlet (62) into the introduction chamber (82), does not permeate the gas separation membrane (85), and enters the primary side outlet chamber ( 83) flows out from the second primary side outlet (63) as first compartment air, passes through the gas separation membrane (85), and flows into the secondary side outlet chamber (84). It flows out from the second secondary side outlet (64) as air in the second compartment.

<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) for measuring the oxygen concentration of mixed gas such as air, and a carbon dioxide sensor (95) for measuring the carbon dioxide concentration of mixed gas such as air. and

The oxygen sensor (91) includes a sensor body (92), which is a galvanic cell type sensor, and a sensor case (93) that houses the sensor body (92). The sensor case (93) is attached with 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). The air filter (94) is a membrane filter for capturing dust and the like contained in the inside air. Also, the sensor case (93) is connected to the outlet end of the measurement pipe (125).

The carbon dioxide sensor (95) includes a sensor body (96), which 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. One end of an outlet pipe (98) is connected to the sensor case (97). The other end of the outlet pipe (98) opens into 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 air pressure in the secondary flow path (29b) is slightly higher than the air pressure in the primary flow path (29a). Therefore, when the measurement on-off valve (126) is closed, the air in the secondary flow path (29b) passes through the air filter (94), flows into the oxygen sensor (91), and then flows into the carbon dioxide sensor (91). (95) before entering 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.

<Exhaust pipe for ventilation>
The ventilation exhaust pipe (100) is a pipe for connecting the inside and the outside of the shipping container (1). The ventilation exhaust pipe (100) constitutes a ventilation exhaust passage. As shown in FIG. 1, the ventilation exhaust pipe (100) passes through the casing (20) of the container refrigerator (10). One end of the ventilation exhaust pipe (100) opens into 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 outside fan (16) in the outside 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 inside air. A ventilation exhaust valve (101) is provided in the ventilation exhaust pipe (100). The ventilation exhaust valve (101) is an on-off valve made up of an electromagnetic valve.

<Controller>
The controller (110) includes a CPU (111) that performs control operations and a memory (112) that stores data necessary for the control operations. The measured values of the oxygen sensor (91), the carbon dioxide sensor (95), the first pressure sensor (45), and the second pressure sensor (65) are input to the controller (110). The controller (110) controls the pump unit (35), the first control valve (46), the second control valve (66), the first bypass valve (50), the second bypass valve (70), and the ventilation exhaust valve. (101) to perform a control action to operate. 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 restore the oxygen concentration in the refrigerator to the concentration corresponding to the atmosphere.

－Operating behavior of refrigerator for containers－
The container refrigerator (10) performs a cooling operation to cool the air inside the shipping container (1).

In the cooling operation, the compressor (12) of the refrigerant circuit (11) operates, and refrigerant circulates in the refrigerant circuit (11) to perform a vapor compression refrigeration cycle. In the refrigerant circuit (11), 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) operate. When the outside fan (16) operates, outside air outside the shipping container (1) is drawn into the outside equipment compartment (28) and passes through the condenser (13). In the condenser (13), the refrigerant is condensed by releasing heat to the outside air. When the internal fan (17) operates, internal air in the luggage compartment (5) of the shipping container (1) is sucked into the internal air flow path (29) and passes through the evaporator (15). In the evaporator (15), the refrigerant absorbs heat from the inside air and evaporates.

The flow of air in the refrigerator will be described. The internal air present in the luggage compartment (5) passes through the suction port (26) and flows into the primary flow path (29a) of the internal air flow path (29), whereupon the secondary flow is caused by the internal fan (17). It is blown out to the road (29b). The indoor air that has flowed into the secondary flow path (29b) is cooled while passing through the evaporator (15), and is then blown out from the blowout port (27) into the underfloor flow path (4), where it enters the underfloor flow path ( 4) to flow into the luggage compartment (5).

In the internal air flow path (29), the primary flow path (29a) is positioned on the suction side of the internal fan (17), and the secondary flow path (29b) is positioned on the blowout side of the internal fan (17). . Therefore, during operation of the internal fan (17), the air pressure in the secondary flow path (29b) is slightly higher than the air pressure in the primary flow path (29a).

-Operating operation of indoor air conditioner-
The indoor air conditioner (30) adjusts the composition of the indoor air (oxygen concentration and carbon dioxide concentration of the indoor air in this embodiment) in the cargo room (5) of the shipping container (1). driving. Here, regarding the operating operation of the indoor air conditioner (30) of the present embodiment, the target range for the oxygen concentration of the indoor air is 5%±1%, and the target range for the carbon dioxide concentration of the indoor air is 2%. %±1% will be described as an example.

<Outline of operation of indoor air conditioner>
The indoor air conditioning device (30) of the present embodiment comprises an oxygen concentration reducing operation for reducing the oxygen concentration of the indoor air in the luggage compartment (5), and an operation for reducing the oxygen concentration of the indoor air in the luggage compartment (5). A carbon dioxide concentration reducing operation for reducing the carbon concentration and an oxygen concentration increasing operation for increasing the oxygen concentration of the air inside the luggage compartment (5) are performed.

When the cargo (6) has been loaded into the shipping container (1), 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 indoor air conditioning device (30) performs an oxygen concentration reducing operation for reducing the oxygen concentration of the indoor air. When the oxygen concentration of the indoor air reaches the upper limit (6%) of the target range, the indoor air conditioner (30) stops the oxygen concentration reduction operation.

After the oxygen concentration of the inside air reaches 6% and the operation of stopping the oxygen concentration of the inside air conditioning device (30) is stopped, the oxygen concentration of the inside air is reduced by respiration of the plant, which is the cargo (6). gradually decreases, the carbon dioxide concentration in the air inside the refrigerator gradually increases.

When the carbon dioxide concentration of the inside air reaches the upper limit (3%) of the target range, the inside air conditioner (30) performs a carbon dioxide concentration reduction operation to reduce the carbon dioxide concentration of the inside air. . When the carbon dioxide concentration of the indoor air reaches the lower limit (1%) of the target range, the indoor air conditioner (30) stops the carbon dioxide concentration reduction operation.

Further, when the oxygen concentration of the inside air reaches the lower limit (4%) of the target range, the inside air conditioner (30) performs an oxygen concentration increasing operation to increase the oxygen concentration of the inside air. When the oxygen concentration of the inside air reaches the upper limit (6%) of the target range, the inside air conditioner (30) stops the oxygen concentration increasing operation.

In this way, the indoor air conditioner (30) performs the oxygen concentration reduction operation in order to reduce the oxygen concentration of the indoor air in the luggage compartment (5) from 21% (atmospheric oxygen concentration) to the target range. conduct. In addition, the indoor air conditioner (30) performs a carbon dioxide reduction operation and an oxygen concentration increase operation in order to maintain the oxygen concentration and the carbon dioxide concentration of the inside air in the luggage compartment (5) within their respective target ranges. Repeat as appropriate.

<Oxygen concentration reduction operation>
The oxygen concentration reducing operation of the indoor air conditioner (30) will be described with reference to FIGS. 3 to 5 as appropriate. In this oxygen concentration reducing operation, the first composition adjusting section (40) supplies the first outside air having a low oxygen concentration to the luggage compartment (5), and the second composition adjusting section (60) supplies the first air having a low oxygen concentration. Air inside the warehouse is supplied to the luggage 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 solid lines 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), thereby opening the ventilation exhaust valve (101). Further, the first primary switching valve (56), the first secondary switching valve (58), the second primary switching valve (76), and the second secondary switching valve (78) are all set to the first state. set to

First, when the first pump (36) operates, outside air existing outside the shipping container (1) passes through the air filter (47) and the outside suction pipe (55) to the first pump (36). sucked into The first pump (36) pressurizes and discharges the sucked outside air. The pressure of the outside air discharged by 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 enters the first introduction port (42) of the first separation module (41) as untreated outside air.

In the first separation module (41), untreated outside air that has flowed into the introduction chamber (82) through the first inlet (42) 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 outside air, and the rest is It flows into the primary outlet chamber (83) as first outside air. As described above, the gas separation membrane (85) has a characteristic that the nitrogen permeability is lower than the oxygen permeability. Therefore, as shown in FIG. 5, the oxygen concentration of the first outside air is lower than the oxygen concentration of the untreated outside air, and the oxygen concentration of the second outside air is lower than the oxygen concentration of the untreated outside air. higher than

The first outside air flowing out from the first primary outlet port (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 port (44) of the first separation module (41) into the first secondary pipe (54) is discharged to the outside of the shipping container (1). be done.

Next, when the second pump (37) is actuated, the internal air existing inside the shipping container (1) (specifically, the secondary flow path (29b) of the container refrigerator (10)) is , is sucked into the second pump (37) through the inside suction pipe (75). The second pump (37) pressurizes and discharges the sucked indoor air. The pressure of the outside air discharged by 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 enters 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 inlet (62) 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 air in the second storage, and the rest is 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 the nitrogen permeability is lower than the oxygen permeability. Therefore, as shown in FIG. 5, the oxygen concentration of the first inside air is lower than the oxygen concentration of the untreated outside air, and the oxygen concentration of the second inside air is lower than the oxygen concentration of the untreated outside air. higher than

The first internal air that has flowed out of the second primary side outlet port (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 warehouse that has flowed out from the second secondary side outlet port (64) of the second separation module (61) into the second secondary side pipe (74) is discharged to the outside of the shipping container (1). be 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). Then, 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 flows into the secondary flow path (29b). ) is supplied to the luggage compartment (5) together with the air flowing through.

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

In this way, 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 room (5) is discharged through the ventilation exhaust pipe (100) to the transportation container. (1) is discharged to the outside, and the oxygen concentration of the air inside the luggage compartment (5) is lowered. In addition, in the oxygen concentration reduction operation, the high oxygen concentration air in the second warehouse separated from the untreated air in the warehouse is discharged to the outside of the shipping container (1), so that the inside of the cargo room (5) Decrease the oxygen concentration of the air.

<Operation to reduce carbon dioxide concentration>
The carbon dioxide concentration reducing operation of the indoor 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 section (40) supplies the first outside air having a low oxygen concentration to the luggage compartment (5), and the second composition adjustment section (60) supplies the second air having a low carbon dioxide concentration. 1. Air inside the warehouse is supplied to the luggage compartment (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 solid lines 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 opened. ) to the closed state. Further, 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 first state. set to Then, in each of the first composition adjusting section (40) and the second composition adjusting section (60), air flows in the same manner as in the oxygen concentration reducing operation. 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. is.

In the first composition adjusting section (40), the untreated outside air that has flowed into the first separation module (41) is composed of the first outside air having a higher nitrogen concentration and a lower oxygen concentration than the untreated outside air, It is separated into the second outside air having a lower nitrogen concentration and a higher oxygen concentration than the untreated outside 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). The carbon dioxide concentration of the untreated outside air is substantially the same as the atmospheric carbon dioxide concentration (0.04%). Therefore, the carbon dioxide concentration of the air outside the first compartment can be regarded as substantially zero.

In the second composition adjusting section (60), the untreated inside 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 inside air. The inside air is separated from the second inside air, which has a lower nitrogen concentration and higher oxygen and carbon dioxide concentrations than the untreated inside air. Then, the air in the first warehouse is supplied to the inside of the transport container (1), and the air in the second warehouse is discharged to the outside of the transport container (1).

Normally, during the carbon dioxide concentration reduction operation, the flow rate Qo1 of the first outside air is larger than the second inside air flow rate Qi2 (Qo1>Qi2), similar to the oxygen concentration reduction operation. The air pressure inside the container (1) becomes positive (see Figure 6). That is, the first composition adjusting section (40) supplies the first outside air into the shipping container (1) so that the air pressure inside the shipping container (1) becomes positive. Since the air pressure inside the shipping container (1) is positive, part of the air inside the cargo compartment (5) passes through the ventilation exhaust pipe (100) to the outside of the shipping container (1). Ejected.

In this way, in the carbon dioxide concentration reduction operation, 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 transportation container (1) through the ventilation exhaust pipe (100). , reduce the carbon dioxide concentration of the air inside the luggage compartment (5). In addition, in the carbon dioxide concentration reduction operation, the air in the second warehouse, which is separated from the untreated air in the warehouse and has a high carbon dioxide concentration, is discharged to the outside of the shipping container (1), thereby reducing the Reduces the concentration of carbon dioxide in the air inside the refrigerator.

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

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 dashed line in FIG. 3), and the pump unit ( 35), the drive motor (38) is energized to operate the first pump (36) and the second pump (37), the ventilation exhaust valve (101) is opened, and the measurement on-off valve (126) is opened. to the closed state. Further, the first primary switching valve (56), the first secondary switching valve (58), the second primary switching valve (76), and the second secondary switching valve (78) are all set to the first state. set to

In the first composition adjusting section (40), the outside air discharged from the first pump (36) flows into the first bypass pipe (51), and the nitrogen concentration and the oxygen concentration are maintained in the first primary stage. It flows into the side pipe (53) and then through the supply pipe (120) into the interior of the shipping container (1). On the other hand, in the second composition adjusting section (60), the inside air sucked into the second pump (37) is discharged from the second pump (37) and then passes through the second bypass pipe (71) to the second It flows into the primary side pipe (73) before returning to the interior of the shipping container (1) through the supply pipe (120). Also, part of the internal air in the luggage compartment (5) is discharged to the outside of the shipping container (1) through the ventilation exhaust pipe (100).

Thus, in the oxygen concentration increasing operation, the oxygen concentration in the cargo room (5) is increased by supplying the outside air having a higher oxygen concentration than the inside air into the transport container (1).

- Control operation of the controller -
The controller (110) of the indoor air conditioner (30) monitors the measured values of the oxygen sensor (91) and the carbon dioxide sensor (95). Then, the oxygen sensor (91) and the carbon dioxide sensor (91) and the carbon dioxide sensor (91) are adjusted so that the oxygen concentration and the carbon dioxide concentration of the inside air are kept within their respective target ranges by performing the above-described operation of the indoor air conditioner (30). Based on the measured value of (95), the components of the indoor air conditioner (30) are controlled.

By the way, conventionally, when taking out cargo such as agricultural products transported or stored in a container (1), before opening the door of the container (1), ventilation is performed to return the oxygen concentration of the air inside the warehouse to the atmospheric level. However, ventilation alone takes a long time to raise the oxygen concentration of the air inside the refrigerator to about 21% of that of the atmosphere. Therefore, in the present embodiment, the oxygen concentration recovery operation (oxygen concentration recovery operation) is performed to shorten the time for returning the air in the refrigerator to the atmosphere equivalent.

<Oxygen concentration recovery operation>
The oxygen concentration recovery operation of the indoor air conditioner (30) will be described with reference to FIGS. 3 and 7. FIG.

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 solid lines 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), thereby opening the ventilation exhaust valve (101). 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) operates, outside air existing outside the shipping container (1) passes through the air filter (47) and the outside suction pipe (55) to the first pump (36). sucked into The first pump (36) pressurizes and discharges the sucked outside air. The pressure of the outside air discharged by 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 enters the first introduction port (42) of the first separation module (41) as untreated outside air.

In the first separation module (41), untreated outside air that has flowed into the introduction chamber (82) through the first inlet (42) flows into the hollow fiber gas separation membrane (85). Part of the air flowing inside the hollow fiber gas separation membrane (85) permeates the gas separation membrane (85) and becomes second outside air having an oxygen concentration higher than that of the untreated outside air. The remaining air flows into the primary outlet chamber (83) as first outdoor air having an oxygen concentration lower than that of the untreated outdoor air.

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

Next, when the second pump (37) is actuated, the internal air existing inside the shipping container (1) (specifically, the secondary flow path (29b) of the container refrigerator (10)) is , is sucked into the second pump (37) through the inside suction pipe (75). The second pump (37) pressurizes and discharges the sucked indoor air. The pressure of the outside air discharged by 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 enters 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 inlet (62) flows into the hollow fiber gas separation membrane (85). A part of the air flowing inside the hollow fiber gas separation membrane (85) permeates the gas separation membrane (85) and becomes second storage air having an oxygen concentration higher than that of the untreated outside air. The remaining air flows into the primary side outlet chamber (83) as the first inside air having an oxygen concentration lower than that of the untreated outside air.

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

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

At this time, part of the internal air is discharged to the outside of the shipping container (1) through the ventilation exhaust pipe (100).

In this way, 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 room (5) is discharged through the ventilation exhaust pipe (100) to the transport container. (1) is discharged to the outside, and the oxygen concentration of the air inside the cargo compartment (5) is restored to the oxygen concentration equivalent to the atmosphere.

Then, the oxygen sensor (91) installed in the warehouse detects the oxygen concentration in the luggage compartment (5), and when the oxygen concentration reaches the target concentration (oxygen concentration equivalent to atmospheric air), the oxygen concentration recovery operation is stopped. do. Since the Industrial Safety and Health Law defines the standard value of oxygen deficiency to be less than 18%, the target concentration is not necessarily limited to 21%, and may be set to 18% or more.

Also, the door of the container (1) may be configured to be locked until the oxygen concentration recovery operation is stopped, for example. 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, erroneous operation such as opening the door by mistake during the oxygen concentration recovery operation can be suppressed.

- Effects of the embodiment -
According to this embodiment, for example, if the oxygen concentration recovery operation is performed before opening the door of the container (1), mixed air (high oxygen concentration gas) is supplied to the inner space having a low oxygen concentration. Therefore, the rate of increase in oxygen concentration in the internal space of the container (1) is faster than when air is introduced into the internal space by performing only ventilation. Also, 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 of the air in the internal space with the atmosphere in order to return the internal space to the oxygen concentration equivalent to the atmosphere. On the other hand, in this embodiment, by introducing a high oxygen concentration gas having an oxygen concentration higher than that of the atmospheric air into the internal space, it is possible to shorten the time required to restore the oxygen concentration of the internal space to that of the atmospheric air.

Further, according to the present embodiment, the first composition adjusting section (40) 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; With the second composition control section (60) that separates nitrogen, oxygen and carbon dioxide from the air inside the chamber (1) to generate low-oxygen concentration gas and high-oxygen concentration gas, the high-oxygen Since the concentration gas is supplied to the internal space of the container (1), each gas composition control unit (40, 60 ), and the oxygen concentration can be recovered efficiently.

<<Embodiment 2>>
The indoor air conditioner (30) of Embodiment 2 will be described. The in-chamber air conditioner (30) of the embodiment is the same as the in-chamber air conditioner (30) of the first embodiment except that the first composition adjusting section (40) and the controller (110) are changed. The configuration of the composition adjusting section (60) is the same as that of the first embodiment. Here, the in-compartment air conditioner (30) of the second embodiment will be described with respect to the differences from the in-compartment air conditioner (30) of the first embodiment.

-Structure of the first composition adjusting unit-
The first composition adjusting section (40) of the present embodiment, like the first composition adjusting section (40) of the first embodiment, is the outside air sucked from the outside of the shipping container (1) (untreated outside air). ) into a first outside air and a second outside air. The first composition adjusting section (40) of the present embodiment is configured to separate untreated outside air into first outside air and second outside air by a so-called PSA (Pressure Swing Adsorption) method. , differs from the first composition adjusting section (40) of the first embodiment in this respect.

As shown in FIG. 9, the first composition adjusting section (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 indoor 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 control section (40) of the present embodiment includes a first direction control valve (232) and a second direction control valve (233), a first adsorption column (234) and a second adsorption column (235). and As will be described later, each adsorption column (234, 235) is provided with an adsorbent that adsorbs nitrogen in the air.

<air pump>
The air pump (231) is arranged 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), each of which 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. The first pump mechanism (231a), which is the pressurizing section, and the second pump mechanism (231b), which is the depressurizing section, are both 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 the drive motor (231c), sucks air from the suction port, pressurizes the air, and pressurizes the pressurized air. is discharged from the discharge port.

<Outer air pipe, discharge pipe, filter unit>
One end of an outside air pipe (241) forming an outside air passage is connected to the suction port of the first pump mechanism (231a). The air pipe (241) is provided so as to pass through the unit case (32). The other end of the air pipe (241) located outside the unit case (32) is connected to the filter unit (220).

The filter unit (220) has an air filter (47). The air filter (47) is a filter for capturing dust, salt, and the like contained in outside air. In this embodiment, a breathable and waterproof membrane filter is used as the air filter (47). The filter unit (220) is a box-shaped member, and introduces air (external air) that has passed through the air filter (47) into the outside air pipe (241). Although not shown, the filter unit (220) is arranged downstream of the condenser (13) in the external equipment room (28).

One end of a discharge pipe (242) forming 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 side, one branch pipe is connected to the first direction control valve (232) and the other branch pipe is connected to the second direction control valve (233). , respectively.

<Suction pipe, supply pipe>
One end of a suction pipe (243) forming a suction passage is connected to the suction port of the second pump mechanism (231b). The suction pipe (243) is branched into two branch pipes at the other end side, one branch pipe is connected to the first direction control valve (232) and the other branch pipe is connected to the second direction control valve (233). , respectively.

One end of a supply connection pipe (244) forming 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 of the supply connection pipe (244) to the other end, and prevents backflow of air. The supply side on-off valve (273) is an on-off valve consisting of an electromagnetic valve.

<Direction control valve>
Each of the first direction control valve (232) and the second direction 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 a second state in which the first port communicates with the third port. and a second state in which the port is cut off from the port.

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

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

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

The adsorbents filled in these adsorption cylinders (234, 235) have the property of adsorbing nitrogen components in a pressurized state where the pressure is higher than the atmospheric pressure, and desorbing the nitrogen components in a depressurized state where the pressure is lower than the atmospheric pressure. In this embodiment, the adsorbent is, for example, a porous zeolite having pores with 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 control section (40) of the present embodiment, the first adsorption column (234) and the second adsorption column (235) constitute the first separation section (41). The two adsorption cylinders (234, 235) constituting the first separation section (41) divide the untreated outside air into first outside air having a higher nitrogen concentration and lower oxygen concentration than the untreated outside air, and untreated outside air. The second outside air having a lower nitrogen concentration and a higher oxygen concentration than the outside air is separated.

<Oxygen discharge pipe>
One end of the oxygen discharge pipe (245) forming the oxygen discharge passage is branched into two branch pipes. It is connected to two adsorption cylinders (235) respectively. Each branch pipe of the oxygen discharge pipe (245) is provided with one check valve (261). Each check valve (261) allows air flow in the direction out of the corresponding adsorption column (234, 235) and blocks air flow in the opposite direction.

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

<Purge pipe>
A purge pipe (250) forming a purge passage is connected to each branch pipe of the oxygen discharge pipe (245). The purge pipe (250) has one end connected to a branch pipe connected to the first adsorption column (234) and the other end connected to a branch pipe connected to the second adsorption column (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 on-off valve consisting of an electromagnetic valve. The purge valve (251) is opened when equalizing the pressures of the first adsorption column (234) and the second adsorption column (235). 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) forming 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 comprising an electromagnetic valve. The exhaust opening/closing valve (272) is opened when the air flowing through the supply connection pipe (244) is exhausted outside the refrigerator.

<Connecting pipe for measurement>
A measurement connection pipe (281) forming 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 section (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) in the supply connection pipe (244) and the supply side on-off valve (273). The other end of the measurement connection pipe (281) is connected between the measurement on-off valve (126) in the measurement pipe (125) and the sensor unit (90).

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

<Bypass pipe>
A bypass connection pipe (255) forming 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.

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

-Operating operation of the first composition control unit-
The operation of the first composition adjusting section (40) of this embodiment will be described.

The first composition adjusting section (40) of the present embodiment alternately and repeatedly performs a first operation and a second operation, which will be described later, for a predetermined time (for example, 14.5 seconds), thereby changing the untreated outside air to the first The air outside the first compartment and the air outside the second compartment are separated. Further, the first composition adjusting section (40) of the present embodiment, like the first composition adjusting section (40) of the first embodiment, operates to reduce the oxygen concentration and reduce the carbon dioxide concentration of the indoor air conditioner (30). In each of the operations, an operation is performed to separate the untreated outside air into the first outside air and the second outside air.

<First action>
As shown in FIG. 10, in the first action, 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 adsorption cylinder (234), and the second adsorption cylinder (235) is connected to the suction port of the second pump mechanism (231b). Also, in the first action, the supply side on-off valve (273) is opened and the remaining on-off valves (251, 256, 272, 282) are closed. Then, 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) draws in untreated outside air from the outside air pipe (241), pressurizes it, and supplies the pressurized untreated outside air to the first adsorption cylinder (234). In the first adsorption column (234), nitrogen contained in the supplied untreated outside air is adsorbed by the adsorbent. As a result, the first adsorption column (234) generates second outside air having a lower nitrogen concentration and a higher oxygen concentration than the untreated outside air. 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 column (235). In the second adsorption column (235), the internal pressure is reduced and nitrogen is desorbed from the adsorbent. As a result, the second adsorption column (235) generates the first outside air having a higher nitrogen concentration and a lower oxygen concentration than the untreated outside air. 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 connection 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 action>
As shown in FIG. 11, in the second action, 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 adsorption cylinder (235), and the first adsorption cylinder (234) is connected to the suction port of the second pump mechanism (231b). In the second action, the supply side on-off valve (273) is opened and the remaining on-off valves (251, 256, 272, 282) are closed. Then, in the second operation, a desorption operation targeting the first adsorption cylinder (234) and an adsorption operation targeting the second adsorption cylinder (235) are performed.

The first pump mechanism (231a) draws in untreated outside air from the outside air pipe (241), pressurizes it, and supplies the pressurized untreated outside air to the second adsorption cylinder (235). In the second adsorption column (235), nitrogen contained in the supplied untreated outside air is adsorbed by the adsorbent. As a result, the second adsorption column (235) generates second outside air having a lower nitrogen concentration and a higher oxygen concentration than the untreated outside air. 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 column (234). In the first adsorption column (234), the internal pressure is reduced and nitrogen is desorbed from the adsorbent. As a result, in the first adsorption column (234), 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 connection 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 Embodiment 2, the oxygen concentration recovery operation is performed by the second composition adjusting section (60). At this time, the supply pipe (120) feeds the second in-chamber air (air having a higher oxygen concentration than the in-chamber air) flowing out of the second separation module (61) into the second secondary side pipe and the second secondary side pipe. It flows in 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 flows into the luggage compartment (5) together with the air flowing through the secondary flow path (29b). supplied. Part of the air inside the warehouse is discharged to the outside of the shipping container (1) through the ventilation exhaust pipe (100).

In this way, in the oxygen concentration recovery operation, the air inside the second storage compartment (5) having a high oxygen concentration is supplied to the luggage compartment (5), and at the same time, the air inside the storage compartment (5) is transported through the ventilation exhaust pipe (100). The oxygen concentration of the air inside the cargo room (5) is restored to that of the atmosphere.

The oxygen sensor (91) provided in the storage detects the oxygen concentration in the luggage compartment (5), and when the oxygen concentration reaches the target concentration (oxygen concentration equivalent to atmospheric air), the oxygen concentration recovery operation is stopped.

<<Other embodiments>>
The following modifications may be applied to the indoor air conditioner (30) of each of the above embodiments. The following modifications may be appropriately combined or replaced as long as the function of the indoor air conditioner (30) is not impaired.

- 1st modification -
In the oxygen concentration recovery operation of Embodiment 1, the first primary side switching valve (56), the first secondary side switching valve (58), the second primary side switching valve (76), and the second Although the example in which the oxygen concentration recovery operation (first oxygen concentration recovery operation) of FIG. 7 is performed by setting all the secondary switching valves (78) to the second state has been described, 1. setting all of the primary switching valve (56), the first secondary switching valve (58), the second primary switching valve (76), and the second secondary switching valve (78) to the second state; , the oxygen concentration recovery operation (second oxygen concentration recovery operation) shown in FIG. 8 can be performed.

Further, in the first embodiment, in both the first oxygen concentration recovery operation shown in FIG. 7 and the second oxygen concentration recovery operation shown in FIG. The air inside the second compartment, which has a high oxygen concentration, is returned to the inside of the container (1). The second pump (37) is operated halfway (for example, until the oxygen concentration in the internal space reaches 18%), and thereafter the oxygen recovery operation is performed only by the first pump, or the second pump (37) is operated from the beginning. can be stopped and the oxygen recovery operation can be performed only with the first pump (36). However, the Industrial Safety and Health Law stipulates that the standard value for oxygen deficiency is less than 18%. There is no problem in using it, and the recovery time of the oxygen concentration can be shortened compared to the case where the second pump (37) is stopped halfway.

Further, in both the first oxygen concentration recovery operation and the second oxygen concentration recovery operation of Embodiment 1, at least the second outside air out of the second outside air and the second inside air is transferred to the container ( Ventilation may be performed at the same time as supplying the inside of the storage in 1) so that the oxygen concentration in the storage space approaches that of the atmosphere. In this way, when the oxygen concentration recovery operation is performed, ventilation is also performed at the same time, and by mixing a part of the air supplied to the internal space with the atmospheric air, all the gas is made into the gas generated by the gas composition adjustment part (40, 60). It is possible to save energy more than the case.

Note that the oxygen concentration of the high oxygen concentration gas used for the oxygen concentration recovery operation in the first embodiment and the first modified example is an example, and the opening degrees of the first control valve (46) and the second control valve (66) are By adjusting the pressure of the outside air and the inside air passing through the gas separation membrane (85), the separation performance can be adjusted. However, the operating 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 membranes (85) of the first separation module (41) and the gas separation membranes (85) of the second separation module (61) have characteristics similar to each other. can be different.

-Third modification-
In the indoor air conditioner (30) of Embodiment 1, the first bypass valve (50) controls the flow rate of the untreated outside air flowing into the first separation module (41) and the flow rate of the untreated outside air flowing into the first bypass pipe (51). It may be configured such that the ratio of the flow rate of the untreated outside air to be treated can be changed in multiple stages or continuously. Further, the second bypass valve (70) controls the ratio of the flow rate of the untreated internal air flowing into the second separation module (61) to the flow rate of the untreated internal air flowing into the second bypass pipe (71). , may be configured to be changeable in multiple stages or continuously.

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

-Fifth Modification-
In the indoor air conditioner (30) of Embodiment 1, each of the first composition adjustment section (40) and the second composition adjustment section (60) separates sucked air from each other by a so-called PSA (Pressure Swing Adsorption) method. It may be configured to separate into two types of air with different compositions. Embodiment 2 is an example in which the configuration of the PSA method is used in the second composition control section (60), but the PSA method is used in each of the first composition control section (40) and the second composition control section (60). In the configuration, the composition adjusting unit (40, 60) generates air having a low nitrogen concentration and a high oxygen concentration and a high carbon dioxide concentration by causing the adsorbent to adsorb nitrogen contained in the sucked air; The process of desorbing nitrogen from the agent to produce air with high nitrogen concentration and low oxygen and carbon dioxide concentrations is repeated alternately.

-Sixth modification-
The indoor air conditioner (30) of each of the above embodiments may be provided in a stationary refrigerator or freezer. Further, the indoor air conditioner (30) of each of the above-described embodiments may be provided in a refrigerated/frozen container for land transportation that is transported by truck, railroad, or the like. Further, the indoor air conditioner (30) of each of the above-described embodiments may be provided in a refrigerator/freezer truck in which a box forming a luggage compartment is integrated with a chassis.

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

INDUSTRIAL APPLICABILITY As described above, the present disclosure is useful for an indoor air conditioning device that adjusts the composition of indoor air in a storage.

1 shipping container
30 Chamber air conditioner
40 First composition control unit (gas composition control unit)
53 Primary side pipe (gas passage)
54 1st secondary side pipe (gas passage)
55 Outside suction pipe (gas passage)
60 Second composition control unit (gas composition control unit)
73 Second primary side pipe (gas passage)
74 Second secondary side pipe (gas passage)
75 Inside suction pipe (gas passage)
85 Gas Separation Membrane
100 Ventilation exhaust pipe (ventilation passage)
110 controller
111 CPU (oxygen concentration recovery controller)
120 Supply pipe (gas passage)

Claims (5)

An indoor air conditioning device for adjusting the composition of indoor air inside a storage (1),
a gas composition control unit (40, 60) capable of generating a low-oxygen concentration gas having an oxygen concentration lower than that of the atmosphere and a high-oxygen concentration gas having an oxygen concentration higher than that of the atmosphere;
gas passages (53 to 55, 73 to 75, 120) communicating with the gas composition adjusting unit (40, 60) and the internal and external spaces of the storage (1);
The low-oxygen oxygen gas generated in the gas composition adjusting section (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) that performs an oxygen concentration reduction operation in which the oxygen concentration in the internal space is reduced by discharging to the external space,
The controller (110) supplies the high-oxygen-concentration gas generated by the gas composition control unit (40, 60) to the internal space to return the oxygen concentration in the internal space to the concentration corresponding to the atmosphere. An in-chamber air conditioner comprising an oxygen concentration recovery control section (111) for carrying out a recovery operation. In claim 1,
Equipped with a ventilation passage (100) that communicates with the internal space and the external space of the storage (1),
An indoor air conditioner, wherein the controller (110) simultaneously performs ventilation of the internal space through 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) to obtain a low oxygen concentration gas having a higher nitrogen concentration and a lower oxygen concentration than the atmosphere, and a first composition adjusting section (40) that generates a high oxygen concentration gas having a lower nitrogen concentration and a higher oxygen concentration than the gas separation membrane (85),
The controller (110) supplies the high oxygen concentration gas generated in the first composition control section (40) to the internal space when the oxygen concentration recovery operation is performed. Device. In claim 3,
The gas composition adjusting section (40, 60) separates nitrogen, oxygen and carbon dioxide from the air inside the storage (1), and the nitrogen concentration is higher than the air inside the storage, and the concentration of oxygen and carbon dioxide is higher than that of the inside air. low oxygen concentration gas and high oxygen concentration gas having a lower nitrogen concentration and higher oxygen and carbon dioxide concentrations than the air in the chamber by the gas separation membrane (85). and
The controller (110) supplies the high oxygen concentration gas generated in the second composition control section (60) to the internal space when the oxygen concentration recovery operation is performed. Device. claim1in
Nitrogen and oxygen are separated from the air outside the storage compartment (1), and a low oxygen concentration gas with a higher nitrogen concentration and a lower oxygen concentration than the atmosphere and a high oxygen concentration gas with a lower nitrogen concentration and a higher oxygen concentration than the atmosphere are separated. a gas separation membrane (85) that produces an oxygen-rich gas;
the above Nitrogen, oxygen and carbon dioxide are separated from the air inside the storage compartment (1), and a low oxygen concentration gas with a higher nitrogen concentration and lower oxygen and carbon dioxide concentrations than the air inside the compartment and Adsorption unit (234, 235) provided with an adsorbent capable of generating high oxygen concentration gas with low nitrogen concentration and high oxygen concentration and carbon dioxide concentrationWhen,with
When the oxygen concentration recovery operation is performed, the controller (110) controls thegasAn in-chamber air conditioner, characterized in that the high-oxygen-concentration gas generated in the composition control section (60) is supplied to the internal space.

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