Air composition adjustment device, refrigeration device, and storage compartment

Abstract

An air composition adjustment device (90) adjusts the composition of interior air inside a storage compartment (2). The air composition adjustment device (90) is provided with a composition adjustment unit (100), an air supply unit (40), a detector (160), and a controller (110). The composition adjustment unit (100) supplies, to the storage compartment (2), a processed gas having a different composition from that of exterior air. The air supply unit (40) supplies the exterior air to the storage compartment (2). The detector (160) detects the concentrations of components of the interior air. The controller (110) adjusts, on the basis of values detected by the detector (160), the flow rate of the exterior air supplied to the storage compartment (2) by the air supply unit (40).

Description

Air composition control equipment, refrigeration equipment, and storage facilities

[0001] The present disclosure relates to an air composition adjustment device, a refrigeration device, and a storage cabinet.

[0002] Patent Document 1 discloses an internal air conditioning device that adjusts the composition of the air inside a transport container. The internal air conditioning device adjusts the oxygen and carbon dioxide concentrations of the internal air to maintain the freshness of fruits and vegetables stored in the transport container, which serves as a storage facility. The internal air conditioning device processes external air to generate a treated gas with a different composition from the external air, and supplies the treated gas to the internal space. The internal air conditioning device also operates to supply external air to the internal space.

[0003] Japanese Patent Application Laid-Open No. 2018-148877

[0004] The respiration rate of fruits and vegetables stored in a storage facility varies depending on the type and condition of the fruits and vegetables. For example, if the respiration rate of fruits and vegetables is low, the amount of carbon dioxide produced by the respiration of the fruits and vegetables is also low. Therefore, the operation of the air conditioning device in the storage facility may not be able to raise the carbon dioxide concentration in the air inside the storage facility to the target value, and there is a risk that the air inside the storage facility may not be adjusted to a composition suitable for maintaining the freshness of the fruits and vegetables.

[0005] An object of the present disclosure is to appropriately adjust the composition of the air inside the refrigerator.

[0006] A first aspect of the present disclosure is an air composition adjustment device (90) that adjusts the composition of inside air inside a storage cabinet (2), and includes: a composition adjustment unit (100) that processes outside air to generate a gas to be treated having a composition different from that of the outside air and supplies the gas to the storage cabinet (2); an air supply unit (40) that supplies the outside air to the storage cabinet (2) and is capable of changing the flow rate of the outside air supplied to the storage cabinet (2); a detector (160) that detects the concentration of one or more components of the inside air; and a controller (110) that adjusts the flow rate of the outside air that the air supply unit (40) supplies to the storage cabinet (2) based on the value detected by the detector (160).

[0007] In the first aspect, the controller (110) adjusts the flow rate of outside air supplied to the storage cabinet (2) by the air supply unit (40) based on the value detected by the detector (160). Therefore, the flow rate of outside air supplied to the storage cabinet (2) by the air supply unit (40) can be significantly reduced as needed. As a result, even in cases where the flow rate of outside air supplied to the storage cabinet (2) was too high in the past and the composition of the inside air could not be appropriately set, the controller (110) adjusts the flow rate of outside air supplied to the storage cabinet (2) by the air supply unit (40), making it possible to appropriately set the composition of the inside air.

[0008] A second aspect of the present disclosure is the first aspect, wherein the controller (110) operates in a first control mode in which, with the supply of outside air to the storage cabinet (2) by the air supply unit (40) stopped, the operation of the composition adjustment unit (100) is controlled based on the value detected by the detector (160), and in a second control mode in which, with the composition adjustment unit (100) stopped, the flow rate of the outside air supplied to the storage cabinet (2) by the air supply unit (40) is adjusted based on the value detected by the detector (160).

[0009] In the second aspect, the controller (110) operates in a first control mode and a second control mode. In the first control mode, the controller (110) controls the composition adjustment unit (100) while stopping the supply of outside air to the storage compartment (2) by the air supply unit (40). In the second control mode, the controller (110) adjusts the flow rate of outside air supplied to the storage compartment (2) by the air supply unit (40) while stopping the composition adjustment unit (100).

[0010] A third aspect of the present disclosure is the second aspect, wherein the detector (160) includes an oxygen sensor (161) that detects the oxygen concentration of the inside air and a carbon dioxide sensor (162) that detects the carbon dioxide concentration of the inside air, and the controller (110) terminates the first control mode and executes the second control mode when, during execution of the first control mode, the detection value of the oxygen sensor (161) is lower than a first predetermined value and the detection value of the carbon dioxide sensor (162) is lower than a second predetermined value.

[0011] In the third aspect, when the detected value of the oxygen sensor (161) is lower than a first predetermined value and the detected value of the carbon dioxide sensor (162) is lower than a second predetermined value, the controller (110) switches the control mode to be executed from the first control mode to the second control mode.

[0012] A fourth aspect of the present disclosure is the third aspect, wherein the controller (110) reduces the flow rate of the outside air supplied to the storage (2) by the air supply unit (40) when the rate of increase of the detection value of the oxygen sensor (161) is higher than a third predetermined value during execution of the second control mode.

[0013] When the controller (110) is operating in the second control mode, if the rate of increase in the detected value of the oxygen sensor (161) is high, the flow rate of outside air supplied by the air supply unit (40) to the storage compartment (2) is too high, which may result in an excessive decrease in the carbon dioxide concentration of the inside air. Therefore, the controller (110) of the fourth aspect reduces the flow rate of outside air supplied by the air supply unit (40) to the storage compartment (2) when the rate of increase in the detected value of the oxygen sensor (161) is higher than a third predetermined value during operation of the second control mode. As a result, the decrease in the carbon dioxide concentration of the inside air is suppressed.

[0014] A fifth aspect of the present disclosure is the third or fourth aspect, wherein, during execution of the second control mode, when the detection value of the oxygen sensor (161) is higher than a fourth predetermined value or when the detection value of the carbon dioxide sensor (162) is higher than a fifth predetermined value, the controller (110) terminates the second control mode and executes the first control mode, wherein the fourth predetermined value is higher than the first predetermined value and the fifth predetermined value is higher than the second predetermined value.

[0015] In the fifth aspect, when the detected value of the oxygen sensor (161) is higher than a fourth predetermined value or when the detected value of the carbon dioxide sensor (162) is higher than a fifth predetermined value, the controller (110) switches the control mode to be executed from the second control mode to the first control mode.

[0016] A sixth aspect of the present disclosure is any one of the second to fifth aspects, wherein the composition adjustment unit (100) is capable of performing a gas supply operation of supplying the gas to be treated to the storage container (2) and an air introduction operation of supplying the outside air to the storage container (2), and the controller (110) switches, in the first control mode, between a state in which the composition adjustment unit (100) performs the gas supply operation, a state in which the composition adjustment unit (100) performs the air introduction operation, and a state in which the composition adjustment unit (100) is at rest without performing the gas supply operation or the air introduction operation, based on a value detected by the detector (160).

[0017] The controller (110) of the sixth aspect switches the composition adjustment unit (100) between a state in which a gas supply operation is performed, a state in which an air introduction operation is performed, and a state in which the composition adjustment unit (100) is in a pause state without performing the gas supply operation or the air introduction operation, based on the value detected by the detector (160).

[0018] A seventh aspect of the present disclosure is any one of the first to sixth aspects, wherein the air supply unit (40) includes an air inlet (41a) with a variable opening that connects the outside of the storage cabinet (2) with the inside of the storage cabinet (2), and the controller (110) increases the flow rate of the outside air that the air supply unit (40) supplies to the storage cabinet (2) by increasing the opening of the air inlet (41a), and decreases the flow rate of the outside air that the air supply unit (40) supplies to the storage cabinet (2) by reducing the opening of the air inlet (41a).

[0019] The controller (110) of the seventh aspect changes the flow rate of the outside air supplied to the storage (2) by the air supply part (40) by changing the opening degree of the air inlet (41a).

[0020] An eighth aspect of the present disclosure is any one of the first to sixth aspects, wherein the air supply unit (40) includes an internal fan (35) that circulates internal air inside the storage cabinet (2) and an air inlet (41a) that connects the outside of the storage cabinet (2) with an intake side area of ​​the internal fan (35) inside the storage cabinet (2), and the controller (110) increases the rotation speed of the internal fan (35) to increase the flow rate of the external air that the air supply unit (40) supplies to the storage cabinet (2) and decreases the rotation speed of the internal fan (35) to decrease the flow rate of the external air that the air supply unit (40) supplies to the storage cabinet (2).

[0021] When the rotation speed of the internal fan (35) changes, the pressure in the suction side region of the internal fan (35) inside the storage cabinet (2) changes, and the flow rate of outside air flowing from the outside to the inside of the storage cabinet (2) through the air inlet (41 a) changes. Therefore, the controller (110) of the eighth aspect changes the rotation speed of the internal fan (35) to change the flow rate of outside air supplied to the storage cabinet (2) by the air supply unit (40).

[0022] A ninth aspect of the present disclosure is any one of the first to fifth aspects, wherein the composition adjustment unit (100) is capable of performing a gas supply operation of supplying the gas to be treated to the storage container (2) and an air introduction operation of supplying the outside air to the storage container (2), the composition adjustment unit (100) is capable of adjusting the flow rate of the outside air supplied to the storage container (2) while the air introduction operation is being performed, the composition adjustment unit (100) performing the air introduction operation also serves as the air supply unit (40), and the controller (110) adjusts the flow rate of the outside air supplied to the storage container (2) by the composition adjustment unit (100) performing the air introduction operation based on a value detected by the detector (160).

[0023] In the ninth aspect, the composition adjusting section (100) that performs the air introduction operation also serves as the air supply section (40). The controller (110) adjusts the flow rate of the outside air that is supplied to the storage compartment (2) by the composition adjusting section (100) that performs the air introduction operation, based on the value detected by the detector (160).

[0024] A tenth aspect of the present disclosure is the first or second aspect, wherein the detector (160) includes a carbon dioxide sensor (162) that detects the carbon dioxide concentration of the inside air, the composition adjustment unit (100) is capable of performing a gas supply operation of supplying the gas to be treated to the storage cabinet (2) and an air introduction operation of supplying the outside air to the storage cabinet (2), and the controller (110) adjusts the flow rate of the outside air supplied by the air supply unit (40) to the storage cabinet (2) when the composition adjustment unit (100) has stopped the gas supply operation and the air introduction operation so that the rate of decrease in the detection value of the carbon dioxide sensor (162) is slower than when the composition adjustment unit (100) is performing the air introduction operation.

[0025] The carbon dioxide concentration of the outside air is very low. Therefore, the carbon dioxide concentration of the inside air gradually decreases both when the composition adjustment unit (100) is performing the air introduction operation and when the air supply unit (40) is supplying outside air to the storage compartment. The controller (110) of the tenth aspect adjusts the flow rate of the outside air supplied to the storage compartment (2) by the air supply unit (40) when the composition adjustment unit (100) is halting the gas supply operation and the air introduction operation so that the rate of decrease in the detected value of the carbon dioxide sensor (162) is slower than when the composition adjustment unit (100) is performing the air introduction operation. Therefore, when the air supply unit (40) is supplying outside air to the storage compartment, the decrease in the carbon dioxide concentration of the inside air is suppressed compared to when the composition adjustment unit (100) is performing the air introduction operation.

[0026] An eleventh aspect of the present disclosure is the first or second aspect, wherein the detector (160) includes an oxygen sensor (161) that detects an oxygen concentration of the inside air and a carbon dioxide sensor (162) that detects a carbon dioxide concentration of the inside air, and the controller (110) is capable of executing an oxygen concentration reduction mode in which, with the air supply unit (40) stopping supply of the outside air to the storage compartment (2), the controller (110) controls the operation of the composition adjustment unit (100) so that the detection value of the oxygen sensor (161) decreases from the oxygen concentration of the atmosphere to a sixth predetermined value, and a composition maintenance mode in which, after the oxygen concentration reduction mode ends, the controller (110) controls the operation of the composition adjustment unit (100) and the air supply unit (40) to maintain the composition of the inside air, and during the composition maintenance mode, the controller (110) adjusts the flow rate of the outside air supplied to the storage compartment (2) by the air supply unit (40) based on the detection values ​​of the oxygen sensor (161) and the carbon dioxide sensor (162).

[0027] In an eleventh aspect, the controller (110) sequentially executes an oxygen concentration reduction mode and a composition maintenance mode, and while executing the composition maintenance mode, the controller (110) adjusts the flow rate of outside air supplied to the storage compartment (2) by the air supply unit (40) based on the detection values ​​of the oxygen sensor (161) and the carbon dioxide sensor (162).

[0028] A twelfth aspect of the present disclosure is any one of the first to eleventh aspects, wherein the gas to be treated includes a first gas having a higher nitrogen concentration and a lower oxygen concentration than the outside air, and a second gas having a lower nitrogen concentration and a higher oxygen concentration than the outside air, and the composition adjustment unit (100) includes an air treatment unit (95) that separates the outside air into the first gas and the second gas.

[0029] In the twelfth aspect, the air treatment section (95) of the composition adjustment section (100) separates the outside air into a first gas and a second gas.

[0030] A thirteenth aspect of the present disclosure is the twelfth aspect, wherein the air treatment unit (95) of the composition adjustment unit (100) in the twelfth aspect includes an adsorbent that adsorbs nitrogen, and the composition adjustment unit (100) performs an operation of generating the second gas by adsorbing nitrogen contained in the outside air to the adsorbent of the air treatment unit (95), and an operation of generating the first gas by desorbing nitrogen from the adsorbent of the air treatment unit (95).

[0031] In the thirteenth aspect, the air treatment section (95) of the composition adjustment section (100) separates the outside air into a first gas and a second gas using an adsorbent that adsorbs nitrogen.

[0032] A fourteenth aspect of the present disclosure is a refrigeration system (10) including any one of the first to thirteenth air composition adjustment devices (90) and a refrigerant circuit (11) that performs a refrigeration cycle to adjust the temperature of the air inside the storage compartment.

[0033] The refrigeration system (10) of the fourteenth aspect adjusts the composition of the inside air by the operation of the air composition adjustment device (90), and adjusts the temperature of the inside air by the operation of the refrigerant circuit (11).

[0034] A fifteenth aspect of the present disclosure is a storage cabinet including the refrigeration system (10) of the fourteenth aspect.

[0035] A storage (2) according to a fifteenth aspect includes a refrigeration system (10) having an air composition regulator (90) and a refrigerant circuit (11).

[0036] FIG. 1 is a schematic perspective view of a transport refrigeration unit according to an embodiment. FIG. 2 is a cross-sectional view of a transport container equipped with the transport refrigeration unit according to an embodiment. FIG. 3 is a piping diagram showing a refrigerant circuit of the transport refrigeration unit according to an embodiment. FIG. 4 is a schematic front view of a ventilation system. FIG. 4(A) shows a state in which the opening / closing cover is in a closed position, FIG. 4(B) shows a state in which the opening / closing cover is in an intermediate position, and FIG. 4(C) shows a state in which the opening / closing cover is in a fully open position. FIG. 5 is a piping diagram showing the configuration of an internal air conditioning unit according to an embodiment. FIG. 6 is a diagram equivalent to FIG. 5 showing an internal air conditioning unit performing a first gas supply operation. FIG. 7 is a diagram equivalent to FIG. 5 showing an internal air conditioning unit performing a second gas supply operation. FIG. 8 is a diagram equivalent to FIG. 5 showing an internal air conditioning unit performing an air introduction operation. FIG. 9 is a block diagram showing the configuration of a controller provided in an air composition adjustment unit according to an embodiment. FIG. 10 is a flow chart showing the operation performed by the controller according to an embodiment.

[0037] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following description, terms such as "front," "rear," "up," "down," "right," and "left" are based on the directions indicated by the arrows in FIG.

[0038] The present disclosure relates to a transport container (1). The transport container (1) is a reefer container capable of controlling the temperature inside. The transport container (1) is a container that can store oxygen (O ) from the air. ２ ) and carbon dioxide (CO ２ ) are used to transport perishables (e.g., fruits, vegetables, flowers, etc.) that breathe and release CO₂.

[0039] As shown in Figures 1 and 2, the transport container (1) includes a container body (2) and a transport refrigeration unit (10). The transport refrigeration unit (10) is attached to the container body (2). The transport container (1) is used for marine transportation. The transport container (1) is transported by a marine transport vehicle such as a ship.

[0040] - Container body - The container body (2) is a storage space for storing the perishables described above.

[0041] The container body (2) is formed in the shape of a hollow box. The container body (2) is formed horizontally long. An opening is formed at one longitudinal end of the container body (2). The opening of the container body (2) is closed by a transport refrigeration unit (10). A storage space (5) for storing perishable cargo is formed inside the container body (2).

[0042] A floor plate (3) for placing cargo is disposed at the bottom of the storage space (5). An underfloor flow path (4) for flowing air blown out by the transport refrigeration unit (10) is formed between the floor plate (3) and the bottom plate of the container body (2). The underfloor flow path (4) is a flow path that extends in the longitudinal direction of the container body (2) along the bottom plate of the container body (2). One end of the underfloor flow path (4) is connected to the air outlet (27) of the transport refrigeration unit (10), and the other end is connected to the space above the floor plate (3) (i.e., the space where cargo is stored).

[0043] - Refrigeration Unit for Transport - The refrigeration unit for transport (10) includes a casing (20), a refrigerant circuit (11) that performs a refrigeration cycle, an external fan (34), and an internal fan (35).

[0044] <Casing> The casing (20) includes an outer wall (21), an inner wall (22), a back panel (24), and a partition plate (25). As will be described later, the casing (20) is provided with a refrigerant circuit (11), an outer fan (34), and an inner fan (35).

[0045] The exterior wall (21) is a plate-like member arranged to cover the open end of the container body (2). The lower part of the exterior wall (21) bulges inward from the container body (2). The interior wall (22) is a plate-like member shaped to fit the exterior wall (21). The interior wall (22) is arranged to cover the inner surface of the exterior wall (21) of the container body (2). A heat insulating material (23) is filled in the space between the exterior wall (21) and the interior wall (22).

[0046] The casing (20) has a lower portion recessed toward the inside of the container body (2). The lower portion of the casing (20) forms an external equipment chamber (28) that communicates with the external space of the transport container (1). An external fan (34) is disposed in the external equipment chamber (28).

[0047] The back plate (24) is a generally rectangular flat plate-like member. The back plate (24) is disposed inside the container body (2) relative to the interior wall portion (22), and forms an interior air flow path (29) between the back plate (24) and the interior wall portion (22). The upper end of the interior air flow path (29) forms the suction port (26) of the casing (20), and the lower end thereof forms the air outlet (27) of the casing (20).

[0048] The partition plate (25) is a plate-like member arranged to divide the internal air flow path (29) into upper and lower portions. The partition plate (25) is arranged at the top of the internal air flow path (29). The partition plate (25) divides the internal air flow path (29) into a primary flow path (29a) above the partition plate (25) and a secondary flow path (29b) below the partition plate (25). The primary flow path (29a) communicates with the storage space (5) via the suction port (26). The secondary flow path (29b) communicates with the underfloor flow path (4) via the air outlet (27). An internal fan (35) is attached to the partition plate (25). The internal fan (35) is arranged to blow air drawn in from the primary flow path (29a) into the secondary flow path (29b).

[0049] <Refrigerant Circuit> As shown in Fig. 3, the refrigerant circuit (11) is a closed circuit formed by connecting a compressor (12), an external heat exchanger (13), an expansion valve (14), and an internal heat exchanger (15) with piping. When the compressor (12) is operated, refrigerant circulates through the refrigerant circuit (11), thereby performing a vapor compression refrigeration cycle. As shown in Fig. 2, the external heat exchanger (13) is disposed in the external equipment compartment (28), and the internal heat exchanger (15) is disposed in the secondary flow path (29b) of the internal air flow path (29). The compressor (12) is also disposed in the external equipment compartment (28).

[0050] —Operation of the Transport Refrigeration System— The transport refrigeration system (10) performs a cooling operation to cool the air inside the transport container (1).

[0051] In the cooling operation, the compressor (12) of the refrigerant circuit (11) operates, and a vapor compression refrigeration cycle is performed by circulating the refrigerant in the refrigerant circuit (11). In the refrigerant circuit (11), the refrigerant discharged from the compressor (12) passes through the external heat exchanger (13), the expansion valve (14), and the internal heat exchanger (15) in this order, and is then drawn into the compressor (12) and compressed.

[0052] In addition, during cooling operation, the external fan (34) and the internal fan (35) are operated. When the external fan (34) is operated, external air outside the transport container (1) is sucked into the external equipment room (28) and passes through the external heat exchanger (13). In the external heat exchanger (13), the refrigerant dissipates heat into the external air and condenses. When the internal fan (35) is operated, internal air in the storage space (5) of the transport container (1) is sucked into the internal air flow path (29) and passes through the internal heat exchanger (15). In the internal heat exchanger (15), the refrigerant absorbs heat from the internal air and evaporates.

[0053] The flow of the air inside the storage space (5) will be described. The air inside the storage space (5) flows through the inlet (26) into the primary flow path (29a) of the air flow path (29) and is then blown out into the secondary flow path (29b) by the interior fan (35). The air inside the storage space (5) flows into the secondary flow path (29b) and is cooled as it passes through the interior heat exchanger (15). The air is then blown out through the outlet (27) into the underfloor flow path (4) and flows through the underfloor flow path (4) into the storage space (5).

[0054] In the internal air flow path (29), the primary flow path (29a) is located on the suction side of the internal fan (35), and the secondary flow path (29b) is located on the outlet side of the internal fan (35). Therefore, while the internal fan (35) is operating, the air pressure in the secondary flow path (29b) becomes slightly higher than the air pressure in the primary flow path (29a).

[0055] -Air Composition Adjustment Device- The transport refrigeration unit (10) includes an air composition adjustment device (90). The air composition adjustment device (90) also includes a ventilation system (40), an internal air conditioner (100), and a controller (110).

[0056] The ventilation device (40) is an air supply unit that supplies atmospheric air, which is outside the storage compartment, to the storage space (5) of the storage compartment (2). The ventilation device (40) is capable of changing the flow rate of the outside air supplied to the storage space (5).

[0057] The indoor air conditioner (100) treats atmospheric air, which is the air outside the cabinet, to generate a gas to be treated, which has a composition different from that of the air outside the cabinet. The indoor air conditioner (100) is a composition adjustment unit that supplies the generated gas to be treated to a storage space (5) of a storage cabinet (2).

[0058] - Ventilation Device - The ventilation device (40) will be described. The ventilation device (40) ventilates the storage space (5) of the container body (2). The ventilation device (40) has an air supply function of supplying outside air to the storage space (5) and an exhaust function of discharging inside air to the outside space (6).

[0059] <Configuration of Ventilation Device> As shown in Fig. 1, the ventilation device (40) is disposed in the upper left portion of the casing (20) of the transport refrigeration unit (10). As shown in Fig. 2, the ventilation device (40) is provided in a ventilation mounting opening (38) formed in the casing (20). The ventilation mounting opening (38) penetrates the casing (20) in the front-rear direction.

[0060] As shown in Fig. 2, an air supply passageway (41) and an exhaust passageway (42) are formed inside the ventilation device (40). The air supply passageway (41) and the exhaust passageway (42) connect the storage space (5) and the external space (6).

[0061] Specifically, the air supply passage (41) connects the primary flow path (29a) of the internal air flow path (29) with the external space (6). The end of the air supply passage (41) on the external space (6) side is the air supply communication port (41a). The air supply communication port (41a) is an air inlet port that connects the external space (6) with the inside of the container body (2). The exhaust passage (42) connects the secondary flow path (29b) of the internal air flow path (29) with the external space (6). The end of the exhaust passage (42) on the external space (6) side is the exhaust communication port (42a). The air supply communication port (41a) and the exhaust communication port (42a) are slightly elongated openings extending in the circumferential direction.

[0062] The ventilation device (40) includes an open-close lid (45). The open-close lid (45) is a disk-shaped member. The open-close lid (45) is provided to cover the air supply communication port (41 a) and the air exhaust communication port (42 a). The open-close lid (45) is driven by a motor (not shown) and is rotatable about its central axis.

[0063] As shown in FIG. 4 , the open-close lid (45) is formed with an air intake opening (46) and an exhaust opening (47). The air intake opening (46) and the exhaust opening (47) each penetrate the open-close lid (45) in the thickness direction. The shape of the air intake opening (46) is the same as the shape of the air intake communication port (41 a). The shape of the exhaust opening (47) is the same as the shape of the exhaust communication port (42 a). The air intake opening (46) and the exhaust opening (47) are formed in the open-close lid (45) at positions such that when the entire air intake opening (46) overlaps with the air intake communication port (41 a), the entire exhaust opening (47) overlaps with the exhaust communication port (42 a).

[0064] <Operation of the ventilation device> The ventilation device (40) is configured to be able to adjust the flow rate of outside air supplied to the storage space (5) (intake air flow rate) and the flow rate of inside air discharged from the storage space (5) (exhaust air flow rate) by rotating the opening / closing lid (45).

[0065] Specifically, when the open-close cover (45) is rotated, the area of ​​the portion of the air supply communication port (41a) that overlaps with the air supply opening (46) and the area of ​​the portion of the air exhaust communication port (42a) that overlaps with the air exhaust opening (47) change. Outside air flows into the air supply passage (41) through the portion of the air supply communication port (41a) that overlaps with the air supply opening (46) and then flows into the storage space (5). Inside air flowing through the air exhaust passage (42) flows into the outside space (6) through the portion of the air exhaust communication port (42a) that overlaps with the air exhaust opening (47).

[0066] Therefore, increasing the area of ​​the portion of the air supply communication port (41a) that overlaps with the air supply opening (46) increases the supply air flow rate, while decreasing the area of ​​that portion decreases the supply air flow rate.Furthermore, increasing the area of ​​the portion of the exhaust communication port (42a) that overlaps with the exhaust opening (47) increases the exhaust flow rate, while decreasing the area of ​​that portion decreases the exhaust flow rate.

[0067] When the open-close lid (45) is in the position shown in Figure 4(A), the entire air supply communication opening (41a) is covered by the open-close lid (45), and the entire air exhaust communication opening (42a) is covered by the open-close lid (45). Therefore, the area of ​​the portion of the air supply communication opening (41a) that overlaps with the air supply opening (46) and the area of ​​the portion of the air exhaust communication opening (42a) that overlaps with the air exhaust opening (47) are both zero. In other words, the air supply passage (41) and the air exhaust passage (42) are fully closed. Therefore, in this state, the air supply flow rate and the air exhaust flow rate are both zero.

[0068] When the open-close cover (45) is in the position shown in Figure 4(C), the entire air intake communication port (41a) overlaps with the air intake opening (46), and the entire air exhaust communication port (42a) overlaps with the air exhaust opening (47). Therefore, the area of ​​the portion of the air intake communication port (41a) that overlaps with the air intake opening (46) (the dotted portion in Figure 4(C)) and the area of ​​the portion of the air exhaust communication port (42a) that overlaps with the air exhaust opening (47) (the dotted portion in Figure 4(C)) are both maximized. In other words, the air intake passage (41) and the air exhaust passage (42) are fully open. Therefore, in this state, the air intake flow rate and the air exhaust flow rate are both at their maximum.

[0069] When the open-close cover (45) is in the position shown in Figure 4(B), a portion of the air intake communication port (41a) overlaps with the air intake opening (46), and a portion of the exhaust communication port (42a) overlaps with the exhaust opening (47). Therefore, the area of ​​the portion of the air intake communication port (41a) that overlaps with the air intake opening (46) (the dotted portion in Figure 4(B)) and the area of ​​the portion of the exhaust communication port (42a) that overlaps with the exhaust opening (47) (the dotted portion in Figure 4(B)) each become intermediate areas that are smaller than the maximum. Therefore, in this state, the air intake flow rate and the exhaust flow rate each become intermediate flow rates that are greater than zero and smaller than the maximum flow rate.

[0070] -Interior Air Conditioning Device- The interior air conditioning device (100) is provided in the transport refrigeration unit (10) for so-called controlled atmosphere (CA) transport. The interior air conditioning device (100) adjusts the composition of air in the storage space (5) of the transport container (1).

[0071] 5, the indoor air conditioner (100) includes a filter unit (220), a main unit (200), a gas supply pipe (275), a gas exhaust pipe (276), a sensor unit (160), and a ventilation exhaust pipe (150). The indoor air conditioner (100) is a gas separation device of a so-called PSA (Pressure Swing Adsorption) type.

[0072] The indoor air conditioner (100) treats atmospheric air, which is outside the compartment, to generate a gas to be treated. Specifically, the indoor air conditioner (100) separates the outside air into a nitrogen-enriched gas having a higher nitrogen concentration and a lower oxygen concentration than the outside air, and an oxygen-enriched gas having a lower nitrogen concentration and a higher oxygen concentration than the outside air. The nitrogen-enriched gas is a first gas, and the oxygen-enriched gas is a second gas.

[0073] <Filter Unit, External Air Pipe> The filter unit (220) is a box-shaped member. The filter unit (220) is installed in the external equipment room (28) of the transport refrigeration unit (10). The filter unit (220) includes an air filter (221). The air filter (221) is a filter for capturing dust, salt, and the like contained in the external air. The air filter (221) of this embodiment is a breathable and waterproof membrane filter.

[0074] The filter unit (220) is connected to the main unit (200) via an outside air pipe (241). One end of the outside air pipe (241) is connected to the filter unit (220). The other end of the outside air pipe (241) is connected to an air pump (231) described below. The outside air pipe (241) guides outside air (atmospheric air) that has passed through the air filter (221) to the air pump (231).

[0075] <Main Unit> The main unit (200) is installed in the external equipment room (28) of the transport refrigeration unit (10). The main unit (200) includes an air pump (231), a first adsorption column (234), a second adsorption column (235), a first switching valve (232), a second switching valve (233), and a unit case (201) that accommodates these components. The unit case (201) accommodates an inlet pipe (242), a suction pipe (243), a first gas pipe (244), and a second gas pipe (245).

[0076] <Air Pump> The air pump (231) includes a pressurization-side pump (231a), a decompression-side pump (231b), and a drive motor (231c). The pressurization-side pump (231a) and the decompression-side pump (231b) each suck in and discharge air. The pressurization-side pump (231a) and the decompression-side pump (231b) are connected to a drive shaft of a single drive motor (231c). In the air pump (231), both the pressurization-side pump (231a) and the decompression-side pump (231b) are driven by a single drive motor (231c).

[0077] The other end of the outside air pipe (241) is connected to the inlet of the pressurization pump (231a). One end of an introduction pipe (242) is connected to the discharge port of the pressurization pump (231a). The pressurization pump (231a) supplies the air to be treated, which is sucked in through the outside air pipe (241), to the first adsorption column (234) and the second adsorption column (235) through the introduction pipe (242).

[0078] A suction pipe (243) is connected to the inlet of the decompression-side pump (231b). A first gas pipe (244) is connected to the discharge port of the decompression-side pump (231b). The decompression-side pump (231b) discharges gas sucked from the first adsorption column (234) and the second adsorption column (235) through the suction pipe (243) into the first gas pipe (244).

[0079] <Inlet Pipe> The inlet pipe (242) is a pipe that introduces the air to be treated discharged from the pressurizing pump (231a) to the first adsorption column (234) and the second adsorption column (235). One end of the inlet pipe (242) is connected to the discharge port of the pressurizing pump (231a). The other end of the inlet pipe (242) branches into two branch pipes, one of which is connected to the first selector valve (232) and the other of which is connected to the second selector valve (233).

[0080] <Suction Pipe> The suction pipe (243) is a pipe that guides the gas flowing out from the first adsorption column (234) and the second adsorption column (235) to the pressure reduction pump (231b). One end of the suction pipe (243) is connected to the suction port of the pressure reduction pump (231b). The other end of the suction pipe (243) branches into two branch pipes, one of which is connected to the first selector valve (232) and the other of which is connected to the second selector valve (233).

[0081] <First Gas Pipe> The first gas pipe (244) is a pipe through which the nitrogen-rich gas discharged from the pressure-reducing pump (231b) flows. The first gas pipe (244) constitutes a first gas passage through which the nitrogen-rich gas flows. One end of the first gas pipe (244) is connected to the discharge port of the pressure-reducing pump (231b). The other end of the first gas pipe (244) is connected to the gas supply pipe (275).

[0082] The first gas pipe (244) is provided with a check valve (264). The check valve (264) allows gas to flow only in a direction from one end to the other end of the first gas pipe (244) and blocks gas from flowing in the opposite direction.

[0083] <Switching Valve> Each of the first switching valve (232) and the second switching valve (233) is a switching valve having three ports. Each of the first switching valve (232) and the second switching valve (233) is configured to be switchable between a first state (indicated by a solid line in FIG. 3 ) in which the first port is connected to the second port and is isolated from the third port, and a second state (indicated by a dashed line in FIG. 3 ) in which the first port is connected to the third port and is isolated from the second port.

[0084] The first selector valve (232) has a first port connected to one end of the first adsorption column (234). The first selector valve (232) has a second port connected to a branch pipe of the inlet pipe (242) and a third port connected to a branch pipe of the suction pipe (243). The first selector valve (232) switches the first adsorption column (234) between a state where it is connected to the pressurization pump (231a) and a state where it is connected to the decompression pump (231b).

[0085] The second selector valve (233) has a first port connected to one end of the second adsorption column (235). A branch pipe of the inlet pipe (242) is connected to a second port of the second selector valve (233), and a branch pipe of the suction pipe (243) is connected to a third port of the second selector valve (233). The second selector valve (233) switches the second adsorption column (235) between a state where it is connected to the pressurization pump (231a) and a state where it is connected to the decompression pump (231b).

[0086] <Adsorption column> Each of the first adsorption column (234) and the second adsorption column (235) is a component including a cylindrical container with both ends closed and an adsorbent filled in the container. The adsorption columns (234, 235) separate the air to be treated (outside the chamber air in this embodiment) into an oxygen-enriched gas and a nitrogen-enriched gas by using the adsorbent.

[0087] The adsorbent packed in the adsorption columns (234, 235) has the property of adsorbing nitrogen and water (water vapor) in the air to be treated under a pressurized condition where the pressure is higher than atmospheric pressure, and desorbing nitrogen and water under a reduced pressure condition where the pressure is lower than atmospheric pressure. An example of an adsorbent having such a property is 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).

[0088] The first adsorption column (234) and the second adsorption column (235), together with the first switching valve (232) and the second switching valve (233), constitute an air treatment section (95).

[0089] <Second Gas Pipe> The second gas pipe (245) includes a trunk pipe (246), a first branch pipe (247a), and a second branch pipe (247b). The second gas pipe (245) constitutes a second gas passage through which oxygen-enriched gas flows.

[0090] The first branch pipe (247a) is a pipe that connects the other end of the first adsorption column (234) to one end of the trunk pipe (246). The second branch pipe (247b) is a pipe that connects the other end of the second adsorption column (235) to one end of the trunk pipe (246). The first branch pipe (247a) and the second branch pipe (247b) are each provided with a check valve (261). Each check valve (261) allows air to flow in the outgoing direction from the corresponding adsorption column (234, 235) and blocks air from flowing in the opposite direction.

[0091] As described above, the first branch pipe (247a) and the second branch pipe (247b) are connected to one end of the trunk pipe (246). The other end of the trunk pipe (246) is connected to the gas exhaust pipe (276), which will be described later. The trunk pipe (246) is provided with an orifice (263) and a check valve (262) in this order from one end to the other. The check valve (262) allows air to flow from one end of the trunk pipe (246) to the other end and blocks air from flowing in the opposite direction.

[0092] <Purge Pipe> A purge pipe (250) is connected to each of the first branch pipe (247a) and the second branch pipe (247b) of the second gas pipe (245). One end of the purge pipe (250) is connected to the first branch pipe (247a) and the other end is connected to the second branch pipe (247b). One end of the purge pipe (250) is connected to the first branch pipe (247a) between the first adsorption column (234) and the check valve (261). The other end of the purge pipe (250) is connected to the second branch pipe (247b) between the second adsorption column (235) and the check valve (261).

[0093] The purge pipe (250) is provided with a purge valve (251). The purge valve (251) is an on-off valve formed of a solenoid valve. The purge valve (251) is opened when equalizing the pressures of the first adsorption column (234) and the second adsorption column (235). In addition, an orifice (252) is provided on each side of the purge valve (251) in the purge pipe (250).

[0094] <Exhaust connecting pipe> An exhaust connecting pipe (271) is connected to the first gas pipe (244). One end of the exhaust connecting pipe (271) is connected to the first gas pipe (244) and the other end is connected to the second gas pipe (245). One end of the exhaust connecting pipe (271) is connected to the first gas pipe (244) between the pressure reducing pump (231b) and the check valve (264). The other end of the exhaust connecting pipe (271) is connected to one end of the gas discharge pipe (276).

[0095] The exhaust connection pipe (271) is provided with a gas exhaust valve (272). The gas exhaust valve (272) is an on-off valve made of a solenoid valve. When the gas exhaust valve (272) is opened, the nitrogen-enriched gas flowing through the first gas pipe (244) is exhausted to the outside of the container body (2).

[0096] <Gas Supply Pipe> As described above, one end of the gas supply pipe (275) is connected to the first gas pipe (244). The gas supply pipe (275) extends to the outside of the unit case (201). The other end of the gas supply pipe (275) opens into the inside air flow path (29) of the transport refrigeration unit (10) downstream of the inside fan (35). The gas supply pipe (275) is a pipe for introducing gas flowing in from one end thereof into the container body (2).

[0097] The gas supply pipe (275) is provided with a gas supply valve (273). The gas supply valve (273) is an on-off valve formed of a solenoid valve.

[0098] <Gas Discharge Pipe> As described above, one end of the gas discharge pipe (276) is connected to the trunk pipe (246) of the second gas pipe (245) and the exhaust connection pipe (271). The gas discharge pipe (276) extends to the outside of the unit case (201). The other end of the gas discharge pipe (276) opens into the external equipment room (28) of the transport container (1). The gas discharge pipe (276) is a pipe for discharging gas that has flowed in from one end of the gas discharge pipe (276) to the outside of the container body (2).

[0099] <Measurement Pipe> A measurement pipe (281) is connected to the first gas pipe (244). The measurement pipe (281) connects the first gas pipe (244) to the sensor unit (160). One end of the measurement pipe (281) is connected to the first gas pipe (244) downstream of the check valve (264). The other end of the measurement pipe (281) is connected to the sensor unit (160).

[0100] The measurement pipe (281) is provided with a measurement on-off valve (282). The measurement on-off valve (282) is an on-off valve formed of a solenoid valve. The measurement on-off valve (282) is opened when the air flowing through the first gas pipe (244) is to be sent to the sensor unit (160).

[0101] <Bypass Pipe> A bypass connecting pipe (255) is connected to the inlet pipe (242). The bypass connecting pipe (255) is a pipe for supplying outside air to the storage space (5) of the transport container (1) by bypassing the first adsorption column (234) and the second adsorption column (235). One end of the bypass connecting pipe (255) is connected between the branch point of the inlet pipe (242) and the pressurization side pump (231a). The other end of the bypass connecting pipe (255) is connected to one end of the gas supply pipe (275).

[0102] The bypass connecting pipe (255) is provided with a bypass valve (256). The bypass valve (256) is an on-off valve formed of a solenoid valve. The bypass valve (256) is opened when the outside air discharged by the pressurizing pump (231a) is to be supplied to the storage space (5) without changing its composition.

[0103] <Sensor Unit> The sensor unit (160) includes an oxygen sensor (161), a carbon dioxide sensor (162), and a sensor case (163). The sensor unit (160) is a detector that detects the concentrations of components of the interior air. The sensor unit (160) is provided in the secondary flow path (29b) of the interior air flow path (29).

[0104] The oxygen sensor (161) is, for example, a zirconia current type sensor that measures the oxygen concentration of a gas mixture such as air. The carbon dioxide sensor (162) is, for example, a non-dispersive infrared (NDIR) type sensor that measures the carbon dioxide concentration of a gas mixture such as air. The oxygen sensor (161) and the carbon dioxide sensor (162) are housed in a sensor case (163).

[0105] The sensor case (163) is a box-shaped member. The sensor case (163) includes an air filter (164). The air filter (164) is a membrane filter for capturing dust and other particles contained in the air inside the refrigerator. The air filter (164) filters the air inside the refrigerator that flows into the sensor case (163).

[0106] A measurement pipe (281) is connected to the sensor case (163). An outlet pipe (165) is also connected to the sensor case (163). The outlet pipe (165) has an inlet end connected to the sensor case (163) and an outlet end opening upstream of the internal fan (35) in the internal air flow path (29). In other words, the outlet end of the outlet pipe (165) opens into the primary flow path (29a) of the internal air flow path (29).

[0107] When the measurement on-off valve (282) is closed, the interior air flows through the sensor case (163). Specifically, the interior air flowing through the secondary flow path (29b) of the interior air flow path (29) passes through the air filter (164) and enters the sensor case (163). After passing through the sensor case (163), the air flows through the outlet pipe (165) and into the primary flow path (29a) of the interior air flow path (29). Therefore, when the measurement on-off valve (282) is closed, the oxygen sensor (161) measures the oxygen concentration of the interior air, and the carbon dioxide sensor (162) measures the carbon dioxide concentration of the interior air.

[0108] On the other hand, when the measurement on-off valve (282) is open, the gas flowing through the measurement pipe (281) flows inside the sensor case (163). Specifically, the gas flowing through the first gas pipe (244) or the bypass connecting pipe (255) flows through the measurement pipe (281) into the sensor case (163), passes through the sensor case (163), flows through the outlet pipe (165), and then flows into the primary flow path (29a) of the internal air flow path (29). Therefore, when the measurement on-off valve (282) is open, the oxygen sensor (161) measures the oxygen concentration of the gas flowing from the measurement pipe (281) into the sensor case (163), and the carbon dioxide sensor (162) measures the carbon dioxide concentration of the gas flowing from the measurement pipe (281) into the sensor case (163).

[0109] <Ventilation Exhaust Pipe> The ventilation exhaust pipe (150) is a pipe for discharging the air inside the transport container (1) to the space outside the container. The ventilation exhaust pipe (150) penetrates the exterior wall (21) and the interior wall (22) of the transport refrigeration unit (10). The ventilation exhaust pipe (150) is provided with a ventilation exhaust valve (151). The ventilation exhaust valve (151) is an on-off valve formed of a solenoid valve.

[0110] -Gas Supply Operation of the Indoor Air Conditioning Device- The indoor air conditioning device (100) performs a gas supply operation. The gas supply operation is an operation in which a first gas is generated by processing outside air and the first gas is supplied to the storage space (5) of the storage cabinet (2). During the gas supply operation, the ventilation exhaust valve (151) is opened.

[0111] In the gas supply operation, the indoor air conditioner (100) alternately and repeatedly performs a first operation and a second operation. The indoor air conditioner (100) alternately and repeatedly performs the first operation and the second operation for a predetermined switching time (e.g., 14 seconds). As a result, the air treatment section (95) of the indoor air conditioner (100) separates the outside air into a nitrogen-rich gas (first gas) and an oxygen-rich gas (second gas).

[0112] 6 , in the first operation, the first selector valve (232) is set to the first state, and the second selector valve (233) is set to the second state. In the first operation, the purge valve (251), the bypass valve (256), and the measurement on-off valve (282) are maintained in a closed state. In the first operation, the air pump (231) is operated to perform an adsorption operation in the first adsorption column (234) and a desorption operation in the second adsorption column (235).

[0113] The pressurizing pump (231a) draws in and pressurizes outside air (atmospheric air) through the outside air pipe (241), and supplies the pressurized outside air to the first adsorption column (234). In the first adsorption column (234), nitrogen and water (water vapor) contained in the supplied outside air are adsorbed by an adsorbent. As a result, an oxygen-enriched gas having a lower nitrogen concentration and a higher oxygen concentration than the outside air is generated in the first adsorption column (234). The oxygen-enriched gas flows from the first adsorption column (234) to the first branch pipe (247a) of the second gas pipe (245), and then passes through the gas exhaust pipe (276) to be discharged to the outside space (6).

[0114] Meanwhile, the decompression-side pump (231b) sucks gas from the second adsorption column (235). In the second adsorption column (235), the internal pressure decreases, causing nitrogen and water to desorb from the adsorbent. As a result, a nitrogen-rich gas having a higher nitrogen concentration and a lower oxygen concentration than the air outside the chamber is generated in the second adsorption column (235). The nitrogen-rich gas flows from the second adsorption column (235) into the suction pipe (243) and is sucked into the decompression-side pump (231b). The decompression-side pump (231b) pressurizes the sucked nitrogen-rich gas and discharges it into the first gas pipe (244). The nitrogen-rich gas flowing through the first gas pipe (244) is supplied to the storage space (5) of the storage cabinet (2) through the gas supply pipe (275).

[0115] 7 , in the second operation, the first selector valve (232) is set to the second state, and the second selector valve (233) is set to the first state. In the second operation, the purge valve (251), the bypass valve (256), and the measurement on-off valve (282) are kept closed. In the second operation, the air pump (231) is operated to perform a desorption operation in the first adsorption column (234) and an adsorption operation in the second adsorption column (235).

[0116] The pressurizing pump (231a) draws in and pressurizes outside air (atmospheric air) through the outside air pipe (241), and supplies the pressurized outside air to the second adsorption column (235). In the second adsorption column (235), nitrogen and water (water vapor) contained in the supplied outside air are adsorbed by an adsorbent. As a result, an oxygen-enriched gas having a lower nitrogen concentration and a higher oxygen concentration than the outside air is generated in the second adsorption column (235). The oxygen-enriched gas flows from the second adsorption column (235) to the second branch pipe (247b) of the second gas pipe (245), and then passes through the gas exhaust pipe (276) to be discharged to the outside space (6).

[0117] Meanwhile, the decompression-side pump (231b) sucks gas from the first adsorption column (234). In the first adsorption column (234), the internal pressure decreases, causing nitrogen and water to desorb from the adsorbent. As a result, a nitrogen-rich gas having a higher nitrogen concentration and a lower oxygen concentration than the air outside the chamber is generated in the first adsorption column (234). The nitrogen-rich gas flows from the first adsorption column (234) into the suction pipe (243) and is sucked into the decompression-side pump (231b). The decompression-side pump (231b) pressurizes the sucked nitrogen-rich gas and discharges it into the first gas pipe (244). The nitrogen-rich gas flowing through the first gas pipe (244) is supplied to the storage space (5) of the storage cabinet (2) through the gas supply pipe (275).

[0118] - Air Intake Operation of the Indoor Air Conditioning Device - The indoor air conditioning device (100) performs an air intake operation, which is an operation of supplying outside air, i.e., atmospheric air, to the storage space (5) of the storage (2) without changing its composition.

[0119] 8 , in the air introduction operation, both the first selector valve (232) and the second selector valve (233) are set to the second state. Furthermore, in the air introduction operation, the gas supply valve (273) and the bypass valve (256) are held open, and the remaining on-off valves (251, 272, 282) are held closed. Furthermore, in the air introduction operation, the air pump (231) is operated, and the ventilation exhaust valve (151) is opened.

[0120] The pressurization pump (231a) draws in outside air (atmosphere) through the outside air pipe (241), pressurizes it, and discharges the pressurized outside air into the inlet pipe (242). The outside air discharged from the pressurization pump (231a) flows through the inlet pipe (242), the bypass connecting pipe (255), and the gas supply pipe (275) in this order, and is supplied to the inside air flow path (29). In this way, in the air introduction operation, air having the same composition as the atmosphere is supplied to the storage space (5) of the transport container (1).

[0121] The decompression-side pump (231b) sucks gas from both the first adsorption column (234) and the second adsorption column (235) and discharges the sucked gas into the first gas pipe (244). The gas discharged by the decompression-side pump (231b) into the first gas pipe (244) flows into the gas supply pipe (275) and is supplied to the internal air flow path (29) together with the external air that has flowed into the gas supply pipe (275) from the bypass connecting pipe (255).

[0122] When the pressure reduction-side pump (231b) sucks gas from the first adsorption column (234) and the second adsorption column (235), the pressure in the first adsorption column (234) and the second adsorption column (235) gradually decreases. Then, when the duration of the air introduction operation exceeds a certain period of time (e.g., 45 seconds), the flow rate of gas sucked by the pressure reduction-side pump (231b) becomes substantially zero.

[0123] 9, the controller (110) includes a microcomputer (111) mounted on a control board and a memory device (112) that stores software for operating the microcomputer (111). The memory device (112) is a semiconductor memory.

[0124] The controller (110) controls the components of the indoor air conditioner (100). Measurement values ​​of the oxygen sensor (161) and the carbon dioxide sensor (162) are input to the controller (110). The controller (110) controls the air pump (231), the first switching valve (136), and the second switching valve (137). The controller (110) also controls the ventilation exhaust valve (151), the purge valve (251), the bypass valve (256), the gas exhaust valve (272), the gas supply valve (273), and the measurement on-off valve (282).

[0125] The controller (110) controls the ventilation device (40). Specifically, the controller (110) adjusts the opening degrees of the air supply communication port (41a) and the air exhaust communication port (42a) by rotating the opening / closing lid (45) of the ventilation device (40). Changing the opening degree of the air supply communication port (41a) changes the flow rate of outside air supplied to the storage space (5) through the air supply passage (41). Changing the opening degree of the air exhaust communication port (42a) changes the flow rate of inside air discharged to the outside space (6) through the air exhaust passage (42).

[0126] --Control Operation of Controller (Outline)-- The control operation performed by the controller (110) will be outlined below.

[0127] <Oxygen Concentration Reduction Mode> When the air composition adjustment device (90) starts operating, the controller (110) executes the oxygen concentration reduction mode. The oxygen concentration reduction mode is a control mode for controlling the air composition adjustment device (90) so that the oxygen concentration of the air inside the refrigerator decreases from the atmospheric oxygen concentration (21%) to a set value SP_O2 of the oxygen concentration. The set value SP_O2 of the oxygen concentration is a sixth predetermined value. The oxygen concentration reduction mode is the process from step ST1 to step ST2 in the flowchart of FIG. 10 .

[0128] <Composition Maintenance Mode> After the oxygen concentration reduction mode is completed, the controller (110) next executes the composition maintenance mode. The composition maintenance mode is a control mode for controlling the air composition adjustment device (90) so that the oxygen concentration and carbon dioxide concentration of the air inside the refrigerator are maintained within their respective allowable ranges. The composition maintenance mode corresponds to the processes from step ST3 to step ST9 in the flowchart of FIG. 10 .

[0129] In this embodiment, the allowable range of the oxygen concentration is equal to or greater than SP_O2-α and equal to or less than SP_O2+α (SP_O2-α≦M_O2≦SP_O2+α). The constant α is, for example, 1%. The measured value M_O2 of the oxygen concentration is the value detected by the oxygen sensor (161). The set value SP_O2 of the oxygen concentration is input to the controller (110) by, for example, the manager of the transport refrigeration system (10). The set value SP_O2 of the oxygen concentration is, for example, 3%. The set value SP_O2 of the oxygen concentration is set to a value according to the type of fruit or vegetable to be stored in the storage space (5).

[0130] The allowable range of the carbon dioxide concentration is equal to or greater than SP_CO2-β and equal to or less than SP_CO2+β (SP_CO2-β≦M_CO2≦SP_CO2+β). The constant β is, for example, 1%. The measured value M_CO2 of the carbon dioxide concentration is the value detected by the carbon dioxide sensor (162). The set value SP_CO2 of the carbon dioxide concentration is input to the controller (110) by the manager of the transport refrigeration system (10), for example. The set value SP_CO2 of the carbon dioxide concentration is, for example, 5%. The set value SP_CO2 of the carbon dioxide concentration is set to a value according to the type of fruit or vegetable to be stored in the storage space (5).

[0131] The controller (110) selectively executes a first control mode and a second control mode in the composition maintenance mode.

[0132] <First Control Mode> The first control mode is a control mode in which the indoor air conditioner (100) is operated while the ventilation device (40) is stopped from supplying and exhausting air. The first control mode corresponds to the processes from step ST3 to step ST5 in the flowchart of Fig. 10. In the first control mode, the controller (110) controls the operation of the indoor air conditioner (100) so that the oxygen concentration and the carbon dioxide concentration of the indoor air are maintained within their respective allowable ranges.

[0133] <Second Control Mode> The second control mode is a control mode in which the ventilation device (40) supplies and exhausts air while the indoor air conditioner (100) is in a stopped state. The second control mode corresponds to the processes from step ST6 to step ST9 in the flowchart of FIG. 10 . The second control mode is executed when, during the composition maintenance mode, it is necessary to increase the oxygen concentration of the indoor air while minimizing the decrease in the carbon dioxide concentration of the indoor air. In the second control mode, the controller (110) adjusts the flow rate of the air supplied by the ventilation device (40) so as to prevent the carbon dioxide concentration of the indoor air from decreasing too much.

[0134] - Control Operation of Controller (Details) - The control operation performed by the controller (110) will be described in detail with reference to the flow chart of FIG.

[0135] <Step ST1> As described above, when the air composition adjustment device (90) starts to operate, the controller (110) executes the oxygen concentration reduction mode.

[0136] In the process of step ST1, the controller (110) sets the open / close cover (45) of the ventilation device (40) to a position that completely covers the air supply communication port (41 a) and the air exhaust communication port (42 a). In this state, both the air supply communication port (41 a) and the air exhaust communication port (42 a) are fully closed, and the ventilation device (40) neither supplies nor exhausts air.

[0137] In the process of step ST1, the controller (110) causes the internal air conditioner (100) to execute a gas supply operation. In the gas supply operation, the internal air conditioner (100) alternately performs a first operation and a second operation to supply a nitrogen-enriched gas (first gas) to the storage space (5) of the container body (2). In the gas supply operation, the ventilation exhaust valve (151) is in an open state, and the air in the storage space (5) is exhausted to the external space (6) through the ventilation exhaust pipe (150). Therefore, the air in the storage space (5) is gradually replaced with the nitrogen-enriched gas, and the oxygen concentration of the internal air in the storage space (5) gradually decreases.

[0138] <Step ST2> When the in-compartment air conditioner (100) is performing the gas supply operation, the controller (110) performs the process of step ST2.

[0139] In the process of step ST2, the controller (110) acquires the detection value of the oxygen sensor (161). The detection value of the oxygen sensor (161) is a measured value M_O2 of the oxygen concentration of the air inside the refrigerator. The controller (110) compares the measured value M_O2 of the oxygen concentration with a set value SP_O2 of the oxygen concentration.

[0140] If the measured oxygen concentration value M_O2 is higher than the set oxygen concentration value SP_O2 (M_O2>SP_O2), the controller (110) causes the indoor air conditioner (100) to continue the gas supply operation and performs the process of step ST2 again. On the other hand, if the measured oxygen concentration value M_O2 is equal to or lower than the set oxygen concentration value SP_O2 (M_O2≦SP_O2), the controller (110) ends the oxygen concentration reduction mode and starts the first control mode, which is the composition maintenance mode.

[0141] <Step ST3> Having started the first control mode of the composition maintaining mode, the controller (110) performs the process of step ST3.

[0142] In the process of step ST3, the controller (110) sets the opening / closing cover (45) of the ventilation device (40) to a position that completely covers the air supply communication port (41 a) and the exhaust communication port (42 a). In this state, both the air supply communication port (41 a) and the exhaust communication port (42 a) are fully closed, and the ventilation device (40) neither supplies nor exhausts air. Note that, if the air supply communication port (41 a) and the exhaust communication port (42 a) are already fully closed at the time the process of step ST3 is started, the controller (110) maintains the position of the opening / closing cover (45) of the ventilation device (40) without changing it.

[0143] In the process of step ST3, the controller (110) controls the operation of the in-compartment air conditioner (100) so that the oxygen concentration and the carbon dioxide concentration of the in-compartment air are maintained within their respective allowable ranges.

[0144] In the process of step ST3, the controller (110) acquires the detection value of the oxygen sensor (161) and the detection value of the carbon dioxide sensor (162). The detection value of the oxygen sensor (161) is a measured value M_O2 of the oxygen concentration of the inside air. The detection value of the carbon dioxide sensor (162) is a measured value M_CO2 of the carbon dioxide concentration of the inside air.

[0145] In the processing of step ST3, the controller (110) switches the in-compartment air conditioning device (100) between a state in which a gas supply operation is performed, a state in which an air introduction operation is performed, and a rest state in which neither a gas supply operation nor an air introduction operation is performed, based on the measured value M_O2 of the oxygen concentration and the measured value M_CO2 of the carbon dioxide concentration.

[0146] When it is necessary to reduce the oxygen concentration of the interior air, the controller (110) causes the interior air conditioner (100) to perform a gas supply operation. When the interior air conditioner (100) performs the gas supply operation, nitrogen-enriched gas is supplied to the storage space (5), and the oxygen concentration of the interior air is reduced.

[0147] The controller (110) causes the indoor air conditioner (100) to perform an air introduction operation when it is necessary to increase the oxygen concentration of the indoor air or when it is necessary to decrease the carbon dioxide concentration of the indoor air. When the indoor air conditioner (100) performs the air introduction operation, outside air (atmosphere) is supplied directly to the storage space (5). Outside air, which is atmospheric air, has an oxygen concentration of 21% and a carbon dioxide concentration of 0.03%. Therefore, when outside air is supplied to the storage space (5), the oxygen concentration of the indoor air increases and the carbon dioxide concentration of the indoor air decreases.

[0148] The controller (110) puts the indoor air conditioner (100) into a sleep state when there is no need to adjust either the oxygen concentration or the carbon dioxide concentration of the indoor air. In the sleep state, the indoor air conditioner (100) performs neither the gas supply operation nor the air introduction operation. Meanwhile, in the storage space (5), the stored fruits and vegetables, etc., breathe. Therefore, while the indoor air conditioner (100) is in the sleep state, the oxygen concentration of the indoor air gradually decreases, and the carbon dioxide concentration of the indoor air gradually increases.

[0149] <Step ST4> The controller (110) performs the process of step ST4 while controlling the indoor air conditioner (100). In the process of step ST4, the controller (110) determines whether or not an instruction to end the composition maintenance mode has been input. The instruction to end the composition maintenance mode is input, for example, when the transportation of fruits and vegetables is completed.

[0150] If an instruction to terminate the composition maintenance mode is input, the controller (110) terminates the composition maintenance mode. On the other hand, if an instruction to terminate the composition maintenance mode is not input, the controller (110) continues the composition maintenance mode and performs the process of step ST5.

[0151] <Step ST5> In the process of step ST5, the controller (110) acquires a measured value M_O2 of the oxygen concentration of the inside air and a measured value M_CO2 of the carbon dioxide concentration of the inside air, and then determines whether the first condition and the second condition are met.

[0152] The first condition is that the measured oxygen concentration M_O2 is equal to or less than the lower limit SP_O2-α of the allowable range of oxygen concentration (M_O2≦SP_O2-α). The lower limit SP_O2-α of the allowable range of oxygen concentration is a first predetermined value. Alternatively, the first condition may be that the measured oxygen concentration M_O2 is lower than the first predetermined value (M_O2<SP_O2-α).

[0153] The second condition is that the measured carbon dioxide concentration value M_CO2 is lower than the set carbon dioxide concentration value SP_CO2 (M_CO2<SP_CO2). The set carbon dioxide concentration value SP_CO2 is a second predetermined value.

[0154] If neither the first condition nor the second condition is satisfied, or if only one of the first condition or the second condition is satisfied, the controller (110) continues to perform the first control mode. Specifically, the controller (110) performs the process of step ST3 again.

[0155] On the other hand, when both the first and second conditions are met, it is necessary to increase the oxygen concentration of the air inside the refrigerator while minimizing the decrease in the carbon dioxide concentration of the air inside the refrigerator, and therefore the controller (110) ends the first control mode and starts the second control mode.

[0156] <Step ST6> Having started the second control mode, the controller (110) performs the process of step ST6.

[0157] In the process of step ST6, the controller (110) puts the indoor air conditioner (100) into a sleep state. In the sleep state, the indoor air conditioner (100) does not perform either the gas supply operation of supplying nitrogen-enriched gas to the storage space (5) or the air introduction operation of supplying outside air to the storage space (5).

[0158] In the process of step ST6, the controller (110) causes the ventilation device (40) to supply and exhaust air. Specifically, the controller (110) rotates the open-close lid (45) of the ventilation device (40) to open a portion of each of the air supply communication port (41 a) and the exhaust communication port (42 a). In this process, the controller (110) moves the open-close lid (45) to a position where the areas of the openings of the air supply communication port (41 a) and the exhaust communication port (42 a) are set to a predetermined initial value that is relatively small.

[0159] When a part of the air supply communication port (41a) is opened, the outside air is supplied to the storage space (5) through the air supply passage (41). When a part of the exhaust communication port (42a) is opened, the inside air that has passed through the exhaust passage (42) is discharged to the outside space (6).

[0160] The opening portion of the air supply communication port (41a) is a portion of the air supply communication port (41a) that overlaps with the air supply opening (46) of the open-close cover (45) (the portion marked with a dot in FIG. 4 ). The initial size of the opening portion of the air supply communication port (41a) is, for example, approximately 1 / 6 of the entire area of ​​the air supply communication port (41a). The opening portion of the exhaust communication port (42a) is a portion of the exhaust communication port (42a) that overlaps with the exhaust opening (47) of the open-close cover (45) (the portion marked with a dot in FIG. 4 ). The initial size of the opening portion of the exhaust communication port (42a) is, for example, approximately 1 / 6 of the entire area of ​​the exhaust communication port (42a).

[0161] <Step ST7> After the process of step ST6, the controller (110) performs the process of step ST7.

[0162] In the process of step ST7, the controller (110) calculates the rate of increase of the measured oxygen concentration value M_O2. Specifically, the controller (110) obtains the measured oxygen concentration value M_O2 at the time when the process of step ST7 is started and the measured oxygen concentration value M_O2 at the time when a predetermined time (e.g., 60 minutes) has elapsed since the process of step ST7 was started, and calculates the amount of change in the measured oxygen concentration value M_O2 per unit time (i.e., the rate of increase of the measured oxygen concentration value M_O2) using these values.

[0163] In the process of step ST7, the controller (110) determines whether a third condition is met. The third condition is that the rate of increase of the measured value M_O2 of the oxygen concentration is higher than a reference rate of increase. The reference rate of increase is a third predetermined value. In this embodiment, the reference rate of increase is the rate of increase of the measured value M_O2 of the oxygen concentration when the indoor air conditioner (100) is performing the air introduction operation in the first control mode of the controller (110).

[0164] If the third condition is met, the controller (110) performs the process of step ST8. On the other hand, if the third condition is not met, the controller (110) performs the process of step ST9.

[0165] <Step ST8> If the rate of increase of the measured oxygen concentration value M_O2 is higher than the reference rate of increase, the flow rate of outside air supplied by the ventilation device (40) to the storage space (5) is too high. When the ventilation device (40) supplies outside air to the storage space (5), inside air containing carbon dioxide is discharged to the outside space (6). Therefore, if the flow rate of outside air supplied by the ventilation device (40) to the storage space (5) is too high, the carbon dioxide concentration of the inside air may be too low. Therefore, in this case, the controller (110) performs the process of step ST8.

[0166] In the process of step ST8, the controller (110) reduces the area of ​​the opening of the air supply communication port (41 a) and the area of ​​the opening of the air exhaust communication port (42 a) by rotating the opening / closing cover (45) of the ventilation device (40). When the area of ​​the opening of the air supply communication port (41 a) is reduced, the flow rate of outside air supplied to the storage space (5) through the air supply passage (41) is reduced. When the area of ​​the opening of the air exhaust communication port (42 a) is reduced, the flow rate of inside air passed through the air exhaust passage (42) and discharged to the outside space (6) is reduced.

[0167] After completing the process of step ST8, the controller (110) performs the process of step ST7 again.

[0168] <Step ST9> If the rate of increase of the measured oxygen concentration value M_O2 is equal to or less than the reference rate of increase, the flow rate of the outside air supplied to the storage space (5) by the ventilation device (40) and the flow rate of the inside air discharged from the storage space (5) by the ventilation device (40) are appropriate. In this case, the controller (110) performs the process of step ST9.

[0169] In the process of step ST9, the controller (110) determines whether the fourth condition and the fifth condition are met.

[0170] The fourth condition is that "the measured oxygen concentration value M_O2 is equal to or greater than the upper limit SP_O2+α of the allowable range of oxygen concentration." The upper limit SP_O2+α of the allowable range of oxygen concentration is a fourth predetermined value. The fourth predetermined value, "the upper limit SP_O2+α of the allowable range of oxygen concentration," is higher than the first predetermined value, "the lower limit SP_O2-α of the allowable range of oxygen concentration." The fourth condition may also be that "the measured oxygen concentration value M_O2 is higher than the fourth predetermined value."

[0171] The fifth condition is that "the measured value M_CO2 of the carbon dioxide concentration is equal to or greater than the upper limit SP_CO2+β of the allowable range of the carbon dioxide concentration." The upper limit SP_CO2+β of the allowable range of the carbon dioxide concentration is a fifth predetermined value. The fifth predetermined value, "the upper limit SP_CO2+β of the allowable range of the carbon dioxide concentration," is higher than the second predetermined value, "the set value SP_CO2 of the carbon dioxide concentration." The fifth condition may also be that "the measured value M_CO2 of the carbon dioxide concentration is higher than the fifth predetermined value."

[0172] If the fourth condition is not met, it is necessary to further increase the oxygen concentration of the air inside the refrigerator. If the fifth condition is not met, it is necessary to continue to minimize the decrease in the carbon dioxide concentration of the air inside the refrigerator. Therefore, if neither the fourth nor the fifth condition is met, the controller (110) continues to operate in the second control mode. Specifically, the controller (110) performs the process of step ST7 again.

[0173] If the fourth condition is met, there is no need to increase the oxygen concentration of the air inside the refrigerator. Furthermore, if the fifth condition is met, there is no need to minimize the decrease in the carbon dioxide concentration of the air inside the refrigerator. Therefore, if one or both of the fourth and fifth conditions are met, the controller (110) ends the second control mode and starts the first control mode. Specifically, the controller (110) performs the process of step ST3 again.

[0174] - Features of the embodiment - The controller (110) of the air composition adjusting device (90) of this embodiment operates in a first control mode and a second control mode in the composition maintenance mode. Therefore, even when fruits and vegetables with a relatively low respiration rate (e.g., berries such as blueberries) are stored in the storage space (5), the carbon dioxide concentration of the air inside the storage space can be maintained within the allowable range (SP_CO2±β) for as long as possible. The reason for this will be explained below.

[0175] In the first control mode, when it is necessary to increase the oxygen concentration of the interior air, the controller (110) causes the interior air conditioner (100) to perform an air introduction operation (see step ST3 in FIG. 10 ). When the interior air conditioner (100) performs the air introduction operation, outside air (atmosphere) is supplied directly to the storage space (5). The outside air, which is the atmosphere, has an oxygen concentration of 21% and a carbon dioxide concentration of 0.03%. Therefore, when the outside air is supplied to the storage space (5), the oxygen concentration of the interior air increases and, at the same time, the carbon dioxide concentration of the interior air decreases.

[0176] Here, the only factor that increases the amount of carbon dioxide contained in the interior air is the respiration of the fruits and vegetables stored in the storage space (5). Therefore, when the respiration rate of the fruits and vegetables stored in the storage space (5) is relatively low, if the interior air conditioner (100) performs an air introduction operation to increase the oxygen concentration of the interior air, the carbon dioxide concentration of the interior air may decrease too much.

[0177] In particular, the internal air conditioning device (100) of this embodiment cannot change the rotation speed of the drive motor (231c) of the air pump (231). Therefore, the flow rate of the external air discharged by the pressurizing pump (231a) cannot be adjusted, and therefore the flow rate of the external air supplied to the storage space (5) during the air introduction operation cannot be adjusted. Therefore, depending on the air introduction operation performed by the internal air conditioning device (100) of this embodiment, there is a risk that the carbon dioxide concentration of the internal air may not be maintained within an allowable range when the respiration rate of fruits and vegetables stored in the storage space (5) is relatively low.

[0178] Therefore, the controller (110) of this embodiment ends the first control mode and starts the second control mode when the first condition and the second condition shown in step ST5 of Fig. 10 are satisfied during execution of the first control mode. In the second control mode, the controller (110) puts the indoor air conditioning device (100) into a sleep state and adjusts the flow rate of the outside air supplied to the storage space (5) by the ventilation device (40).

[0179] The ventilation device (40) of this embodiment can set the flow rate of outside air supplied to the storage space (5) to a value lower than the flow rate of outside air supplied to the storage space (5) by the indoor air conditioner (100) in the air introduction operation. Therefore, by the controller (110) executing the second control mode, the flow rate of outside air supplied to the storage space (5) can be reduced compared to the state in which the indoor air conditioner (100) is performing the air introduction operation.

[0180] Therefore, even if the respiration rate of the fruits and vegetables stored in the storage space (5) is relatively low, the flow rate of the outside air supplied to the storage space (5) can be kept low, thereby increasing the oxygen concentration in the air inside the storage space and minimizing the decrease in the carbon dioxide concentration in the air inside the storage space. As a result, the time during which the carbon dioxide concentration in the air inside the storage space is maintained within an acceptable range can be extended, and the freshness of the fruits and vegetables stored in the storage space (5) can be maintained for a long period of time.

[0181] --Modifications of the embodiment-- The following modifications may be applied to the air composition adjustment device (90) of the above embodiment. Note that the following modifications may be combined or substituted as appropriate, as long as the functionality of the air composition adjustment device (90) is not impaired.

[0182] <First Modification> The ventilation device (40) of the above embodiment may be configured to adjust the flow rate of outside air supplied to the storage space (5) (intake air flow rate) and the flow rate of inside air discharged to the outside space (6) (exhaust air flow rate) by adjusting the rotation speed of the internal fan (35). In this modification, the controller (110) increases the intake air flow rate and the exhaust air flow rate of the ventilation device (40) by increasing the rotation speed of the internal fan (35). In addition, the controller (110) decreases the rotation speed of the internal fan (35) to decrease the intake air flow rate and the exhaust air flow rate of the ventilation device (40).

[0183] Second Modification In the air composition adjustment device (90) of the above embodiment, the in-compartment air conditioner (100) may be configured to function as both a composition adjustment unit and an air supply unit. In this modification, the ventilation device (40) may be provided in the transport refrigeration unit (10) or may be omitted.

[0184] The internal air conditioning device (100) of this modified example is configured to be able to adjust the flow rate of external air supplied to the storage space (5) in the air introducing operation.

[0185] Specifically, in the indoor air conditioner (100) of this modified example, the bypass valve (256) is configured as a motor-operated valve with a variable opening. In this case, the controller (110) increases the intake air flow rate and exhaust air flow rate of the indoor air conditioner (100) performing the air introduction operation by increasing the opening of the bypass valve (256). In addition, the controller (110) decreases the intake air flow rate and exhaust air flow rate of the indoor air conditioner (100) performing the air introduction operation by decreasing the opening of the bypass valve (256).

[0186] The indoor air conditioner (100) of this modified example may be configured to be able to adjust the amount of outdoor air discharged by the pressurizing pump (231a) by varying the rotation speed of the drive motor (231c) of the air pump (231). In this case, the controller (110) increases the supply air flow rate and the exhaust air flow rate of the indoor air conditioner (100) performing the air introduction operation by increasing the rotation speed of the drive motor (231c) of the air pump (231). The controller (110) decreases the supply air flow rate and the exhaust air flow rate of the indoor air conditioner (100) performing the air introduction operation by decreasing the rotation speed of the drive motor (231c) of the air pump (231).

[0187] <Third Modification> In the air composition adjustment device (90) of the above embodiment, the controller (110) may be configured to adjust the intake air flow rate and the exhaust air flow rate of the ventilation device (40) by opening and closing the intake air communication port (41 a) and the exhaust air communication port (42 a) of the ventilation device (40).

[0188] The controller (110) of this modified example periodically moves the open-close lid (45) of the ventilation device (40) to switch the air supply communication opening (41 a) and the air exhaust communication opening (42 a) between a state in which they are partially open and a state in which they are completely covered by the open-close lid (45). The controller (110) of this modified example also adjusts the air supply flow rate and the air exhaust flow rate of the ventilation device (40) by changing the ratio of the time during which the air supply communication opening (41 a) and the air exhaust communication opening (42 a) are partially open to the time during which the air supply communication opening (41 a) and the air exhaust communication opening (42 a) are completely covered by the open-close lid.

[0189] <Fourth Modification> The air treatment unit (95) of the indoor air conditioner (100) of the above embodiment may be configured to separate outside air (atmosphere) into a nitrogen-rich gas (first gas) and an oxygen-rich gas (second gas) using a gas separation membrane. The gas separation membrane has a characteristic that the permeation rate of nitrogen is lower than both the permeation rates of oxygen and carbon dioxide. Therefore, in the air treatment unit (95) of this modification, the outside air is separated into an oxygen-rich gas that has permeated the gas separation membrane and a nitrogen-rich gas that has not permeated the gas separation membrane.

[0190] <Fifth Modification> The air composition adjustment device (90) of the above embodiment may be provided in a stationary refrigerator or freezer. The air composition adjustment device (90) of the above embodiment may also be provided in a land transport container transported by truck, rail, or the like. The air composition adjustment device (90) of the above embodiment may also be provided in a refrigerated / freezer truck in which a box forming a cargo compartment is integrated with the chassis. Thus, the storage facility equipped with the air composition adjustment device (90) of the above embodiment is not limited to a transport container for marine transport, but may also be a transport container for land transport, a box forming a cargo compartment mounted on a truck, or a stationary refrigerator or freezer.

[0191] Although the embodiments and modifications have been described above, it will be understood that various modifications in form and detail are possible without departing from the spirit and scope of the claims. Furthermore, the above embodiments and modifications may be combined or substituted as appropriate as long as the functionality of the subject matter of the present disclosure is not impaired. Furthermore, the terms "first," "second," etc. in the specification and claims are used to distinguish between terms to which these terms are attached, and do not limit the number or order of the terms.

[0192] INDUSTRIAL APPLICABILITY As described above, the present disclosure is useful for air composition adjustment devices, refrigeration devices, and storage cabinets.

[0193] 2 storage cabinet 10 refrigeration device 11 refrigerant circuit 35 in-storage fan 40 ventilation device (air supply section) 41a air supply communication port (air inlet) 90 air composition adjustment device 95 air treatment section 100 in-storage air conditioning device (composition adjustment section) 110 controller 160 sensor unit (detector) 161 oxygen sensor 162 carbon dioxide sensor

Claims

1. An air composition adjustment device (90) for adjusting the composition of inside air inside a storage cabinet (2), comprising: a composition adjustment section (100) that processes outside air to generate a gas to be treated having a composition different from that of the outside air and supplies the gas to the storage cabinet (2); an air supply section (40) that supplies the outside air to the storage cabinet (2) and is capable of changing the flow rate of the outside air supplied to the storage cabinet (2); a detector (160) that detects the concentration of one or more components of the inside air; and a controller (110) that adjusts the flow rate of the outside air supplied to the storage cabinet (2) by the air supply section (40) based on a value detected by the detector (160).

2. The air composition adjustment device as described in claim 1, wherein the controller (110) performs a first control mode in which, with the supply of outside air to the storage facility (2) by the air supply unit (40) being stopped, the operation of the composition adjustment unit (100) is controlled based on the value detected by the detector (160), and a second control mode in which, with the composition adjustment unit (100) being stopped, the flow rate of the outside air supplied by the air supply unit (40) to the storage facility (2) is adjusted based on the value detected by the detector (160).

3. The air composition adjustment device as described in claim 2, wherein the detector (160) includes an oxygen sensor (161) for detecting an oxygen concentration in the interior air, and a carbon dioxide sensor (162) for detecting a carbon dioxide concentration in the interior air, and the controller (110) terminates the first control mode and executes the second control mode when, during execution of the first control mode, the detection value of the oxygen sensor (161) is lower than a first predetermined value and the detection value of the carbon dioxide sensor (162) is lower than a second predetermined value.

4. The air composition adjustment device as described in claim 3, wherein the controller (110) reduces the flow rate of outside air supplied to the storage compartment (2) by the air supply unit (40) when the rate of increase in the detection value of the oxygen sensor (161) is higher than a third predetermined value while the second control mode is being executed.

5. An air composition adjustment device as described in claim 3 or 4, wherein the controller (110) terminates the second control mode and executes the first control mode when, during execution of the second control mode, the detection value of the oxygen sensor (161) is higher than a fourth predetermined value or when the detection value of the carbon dioxide sensor (162) is higher than a fifth predetermined value, and the fourth predetermined value is higher than the first predetermined value and the fifth predetermined value is higher than the second predetermined value.

6. The air composition adjustment device as described in any one of claims 2 to 5, wherein the composition adjustment unit (100) is capable of executing a gas supply operation of supplying the gas to be treated to the storage container (2) and an air introduction operation of supplying the outside air to the storage container (2), and the controller (110) switches, in the first control mode, between a state in which the composition adjustment unit (100) performs the gas supply operation, a state in which the composition adjustment unit (100) performs the air introduction operation, and a state in which the composition adjustment unit (100) is at rest without performing the gas supply operation and the air introduction operation, based on a value detected by the detector (160).

7. The air composition adjustment device of any one of claims 1 to 6, wherein the air supply unit (40) is provided with an air inlet (41a) whose opening is variable, connecting the outside of the storage cabinet (2) with the inside of the storage cabinet (2), and the controller (110) increases the flow rate of the outside air supplied to the storage cabinet (2) by the air supply unit (40) by enlarging the opening of the air inlet (41a), and reduces the flow rate of the outside air supplied to the storage cabinet (2) by the air supply unit (40) by reducing the opening of the air inlet (41a).

8. The air composition adjustment device as claimed in any one of claims 1 to 6, wherein the air supply unit (40) comprises an internal fan (35) for circulating internal air inside the storage cabinet (2) and an air inlet (41a) for communicating between the outside of the storage cabinet (2) and an intake side area of ​​the internal fan (35) inside the storage cabinet (2), and the controller (110) increases the flow rate of the outside air supplied to the storage cabinet (2) by the air supply unit (40) by increasing the rotational speed of the internal fan (35), and reduces the flow rate of the outside air supplied to the storage cabinet (2) by the air supply unit (40) by decreasing the rotational speed of the internal fan (35).

9. An air composition adjustment device as described in any one of claims 1 to 5, wherein the composition adjustment unit (100) is capable of executing a gas supply operation of supplying the gas to be treated to the storage cabinet (2) and an air introduction operation of supplying the outside air to the storage cabinet (2), the composition adjustment unit (100) is capable of adjusting the flow rate of the outside air supplied to the storage cabinet (2) while the air introduction operation is being executed, the composition adjustment unit (100) performing the air introduction operation also serves as the air supply unit (40), and the controller (110) adjusts the flow rate of the outside air supplied to the storage cabinet (2) by the composition adjustment unit (100) performing the air introduction operation based on a value detected by the detector (160).

10. The air composition adjustment device as claimed in claim 1 or 2, wherein the detector (160) includes a carbon dioxide sensor (162) for detecting a carbon dioxide concentration in the air inside the storage compartment, the composition adjustment unit (100) is capable of executing a gas supply operation for supplying the gas to be treated to the storage compartment (2) and an air introduction operation for supplying outside air to the storage compartment (2), and the controller (110) adjusts the flow rate of the outside air supplied by the air supply unit (40) to the storage compartment (2) when the composition adjustment unit (100) has stopped the gas supply operation and the air introduction operation so that the rate of decrease in the detection value of the carbon dioxide sensor (162) is slower than when the composition adjustment unit (100) is performing the air introduction operation.

11. The air composition adjustment device according to claim 1 or 2, wherein the detector (160) includes an oxygen sensor (161) for detecting an oxygen concentration in the inside air, and a carbon dioxide sensor (162) for detecting a carbon dioxide concentration in the inside air, and the controller (110) is capable of executing an oxygen concentration reduction mode for controlling the operation of the composition adjustment unit (100) so that the detection value of the oxygen sensor (161) decreases from the oxygen concentration of the atmosphere to a sixth predetermined value while the supply of outside air to the storage cabinet (2) by the air supply unit (40) is stopped, and a composition maintenance mode for controlling the operation of the composition adjustment unit (100) and the air supply unit (40) to maintain the composition of the inside air after the oxygen concentration reduction mode is terminated, and while the composition maintenance mode is being executed, the flow rate of the outside air supplied by the air supply unit (40) to the storage cabinet (2) is adjusted based on the detection values ​​of the oxygen sensor (161) and the carbon dioxide sensor (162).

12. An air composition adjustment device as described in any one of claims 1 to 11, wherein the gas to be treated includes a first gas having a higher nitrogen concentration and a lower oxygen concentration than the outside air, and a second gas having a lower nitrogen concentration and a higher oxygen concentration than the outside air, and the composition adjustment section (100) is provided with an air treatment section (95) that separates the outside air into the first gas and the second gas.

13. An air composition adjustment device as described in claim 12, wherein the air treatment unit (95) of the composition adjustment unit (100) includes an adsorbent that adsorbs nitrogen, and the composition adjustment unit (100) performs an operation of generating the second gas by adsorbing nitrogen contained in the outside air to the adsorbent of the air treatment unit (95), and an operation of generating the first gas by desorbing nitrogen from the adsorbent of the air treatment unit (95).

14. A refrigeration system comprising: an air composition adjustment device (90) according to any one of claims 1 to 13; and a refrigerant circuit (11) that performs a refrigeration cycle to adjust the temperature of the air inside the refrigeration system.

15. A storage facility comprising a refrigeration device (10) according to claim 14.

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