Air composition conditioning equipment, refrigeration equipment for transportation, and containers for transportation

Abstract

In the air composition regulating device for regulating the air composition of the target space, in the air circuit (3) that supplies the regulated air to the target space, a first passage (75) for introducing external air into the regulating unit (34, 35) and a second passage (76) branching from the first passage (75) and introducing external air into the sensor (51) are provided. In the second passage (76), a moisture removal unit (84) for removing moisture from the air introduced into the sensor (51) is provided, thereby suppressing the possibility of sensor (51) malfunctioning due to moisture coming into contact with the sensor (51) through the passage for introducing external air into the sensor (51).

Description

Technical Field

[0001] This disclosure relates to an air composition conditioning device, a refrigeration device for transportation, and a container for transportation. Background Technology

[0002] To date, air composition regulating devices that adjust the oxygen and carbon dioxide concentrations inside containers used for transporting fresh produce, for example, employ sensors that measure the composition of the air (see, for example, Patent Document 1). In such devices, if the sensor's measurement deviates from the actual value, the oxygen and carbon dioxide concentrations inside the container cannot be adjusted to the desired levels, potentially damaging the fresh produce. Therefore, such air composition regulating devices include a pathway for introducing external air to the sensor, allowing for periodic or intermittent calibration by introducing external air into the sensor.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Publication No. JP08-000168 Summary of the Invention

[0006] -The technical problem the invention aims to solve-

[0007] In the device of Patent Document 1, when external air is introduced into the sensor, moisture is introduced along with the external air, which may cause the sensor to malfunction.

[0008] The purpose of this disclosure is to reduce the possibility of sensor malfunction caused by moisture being introduced into the sensor through the passage for introducing external air.

[0009] - Technical solutions used to solve technical problems -

[0010] The first aspect of this disclosure is based on an air composition conditioning device, which includes:

[0011] Conveying unit 31, which conveys air;

[0012] Adjustment units 34 and 35 adjust the composition of the air;

[0013] Air circuit 3, in which air is introduced into the regulating units 34 and 35 by the conveying unit 31, and the regulated air is supplied to the target space; and

[0014] Sensor 51 is arranged in the object space and measures the composition of air.

[0015] The air composition regulating device is characterized by:

[0016] The air circuit 3 includes a first passage 75 and a second passage 76. The first passage 75 introduces external air into the regulating parts 34 and 35 via the conveying part 31. The second passage 76 branches off from the first passage 75 between the conveying part 31 and the regulating parts 34 and 35 and introduces external air into the sensor 51.

[0017] A moisture removal section 84 is provided in the second passage 76 to remove moisture from the air introduced into the sensor 51.

[0018] In this instruction manual, "moisture removal" means removing at least a portion of the moisture from the air, such as external air, using physical methods.

[0019] In the first aspect, since a moisture removal section 84 is provided in the second passage 76 branching off from the first passage 75, moisture in the external air introduced into the sensor 51 is removed in the second passage 76. Therefore, it is possible to prevent moisture from contacting the sensor 51, thereby suppressing the possibility of sensor 51 malfunctioning.

[0020] The second aspect of this disclosure is, based on the first aspect, characterized in that:

[0021] The air composition regulating device includes a sensor housing 90, and the sensor 51 is housed inside the sensor housing 90.

[0022] The moisture removal unit 84 is arranged between the branch portion of the second passage 76 that branches off from the first passage 75 and the sensor box 90.

[0023] In the second aspect, before the outside air is introduced into the sensor housing 90, the moisture in the outside air is removed by the moisture removal section 84 in the second passage 76, thereby suppressing the contact between moisture and the sensor 51.

[0024] A third aspect of this disclosure is, based on the first aspect, characterized in that:

[0025] The air composition regulating device includes a sensor housing 90, and the sensor 51 is housed inside the sensor housing 90.

[0026] The moisture removal unit 84 is arranged inside the sensor box 90.

[0027] In the third aspect, the moisture removal unit 84 inside the sensor housing 90 removes moisture from the outside air near the sensor 51, thereby suppressing the contact between the sensor 51 and moisture.

[0028] A fourth aspect of this disclosure is, based on any one of the first to third aspects, characterized in that:

[0029] The second passage 76 includes a first portion 76a disposed inside the object space.

[0030] The moisture removal section 84 is arranged in the first part 76a.

[0031] In the fourth aspect, it is possible to remove moisture from the outside air inside the object space. In particular, when the temperature inside the object space is lower than the outside temperature, it is possible to remove moisture generated in the outside air introduced into the sensor 51 due to temperature changes from the outside to the inside of the object space.

[0032] The fifth aspect of this disclosure is, based on the first aspect, characterized in that:

[0033] The air composition regulating device includes a sensor housing 90, and the sensor 51 is housed inside the sensor housing 90.

[0034] The second passage 76 includes a first portion 76a disposed inside the object space.

[0035] The moisture removal unit 84 is arranged in the first part 76a.

[0036] The length of the first portion 76a of the second passage 76 from the inlet portion where air enters the object space to the moisture removal section 84 is longer than the length from the moisture removal section 84 to the sensor box 90.

[0037] In the fifth aspect, since the moisture removal unit 84 is arranged near the sensor housing 90, moisture in the external air introduced into the sensor 51 can be removed by the moisture removal unit 84 at a position outside the sensor housing 90 and near the sensor 51.

[0038] The sixth aspect of this disclosure is, based on the fourth or fifth aspect, characterized in that:

[0039] The conveying unit 31, the adjusting units 34 and 35, the air circuit 3, and the sensor 51 are configured to adjust the composition of the air in the target space cooled by the refrigeration device 10.

[0040] At least a portion of the first part 76a of the second passage 76, from the inlet portion where air enters the object space to the moisture removal section 84, is arranged in the flow path of the air cooled by the refrigeration device 10.

[0041] In the sixth aspect, the external air introduced into the sensor 51 is cooled by the air cooled by the cooling device 10, and the resulting moisture in the external air is removed by the moisture removal unit 84.

[0042] The seventh aspect of this disclosure is, based on any one of the first to sixth aspects, characterized in that:

[0043] The moisture removal unit 84 is composed of a gas-liquid separator 85, which includes a container 86 having an inlet 86a for air to flow in, an outlet 86b for gas from which moisture is separated from the air to flow out, and a drain 86c for water separated from the air to be discharged.

[0044] In the seventh aspect, the moisture contained in the external air introduced into the sensor 51 is removed by the gas-liquid separator 85, thereby inhibiting the contact between the sensor 51 and the moisture.

[0045] The eighth aspect of this disclosure is, based on the seventh aspect, characterized in that:

[0046] The drain outlet 86c is located at the lower part of the container 86.

[0047] In the eighth aspect, since the water separated in the gas-liquid separator 85 is discharged downward by its own weight, the water is easily separated from the external air that flows into the gas-liquid separator 85 next.

[0048] The ninth aspect of this disclosure is, based on the eighth aspect, characterized in that:

[0049] The drain outlet 86c is composed of holes with a diameter of more than 1 mm and less than 3 mm.

[0050] In the ninth aspect, a suitable amount of water can be discharged from the gas-liquid separator 85.

[0051] The tenth aspect of this disclosure is, based on the first aspect, characterized in that:

[0052] The air composition regulating device includes a sensor housing 90, and the sensor 51 is housed inside the sensor housing 90.

[0053] The moisture removal unit 84 is composed of a gas-liquid separator 85, which includes a container 86. The container 86 has an inlet 86a for air to flow in, an outlet 86b for gas from which moisture is separated from the air to flow out, and a drain 86c for discharging the moisture separated from the air.

[0054] The gas-liquid separator 85 is fixed on the sensor box 90.

[0055] In the tenth aspect, by fixing the gas-liquid separator 85 to the sensor housing 90, it is possible to remove moisture from the external air introduced into the sensor 51 at a position outside the sensor housing 90 and close to the sensor 51.

[0056] The eleventh aspect of this disclosure is characterized by, based on any one of the seventh to tenth aspects, that:

[0057] The conveying unit 31, the adjusting units 34 and 35, the air circuit 3, and the sensor 51 are configured to adjust the composition of the air in the target space cooled by the refrigeration device 10.

[0058] The third passage 77, through which the water separated by the gas-liquid separator 85 is discharged, is connected to the drain outlet 86c.

[0059] The third passage 77 is configured to discharge water to a water receiving tray, which receives condensate generated in the refrigeration device 10.

[0060] In the eleventh aspect, it is possible to discharge the moisture in the outside air separated in the gas-liquid separator 85 to the water collection tray of the refrigeration unit 10.

[0061] The twelfth aspect of this disclosure is, based on any one of the first to sixth aspects, characterized in that:

[0062] The moisture removal section 84 includes a heat exchange section 88 and a drainage path 89. The heat exchange section 88 cools the air flowing in the second passage 76, and the drainage path 89 extends downward from the second passage 76 at a position downstream of the heat exchange section 88 or closer to the air flow direction than the heat exchange section 88.

[0063] In the twelfth aspect, moisture in the outside air, after being cooled by the heat exchange unit 88, is discharged from the second passage 76 through the drain passage 89. This suppresses contact between the sensor 51 and water.

[0064] The thirteenth aspect of this disclosure is, based on the twelfth aspect, characterized in that:

[0065] The conveying unit 31, the adjusting units 34 and 35, the air circuit 3, and the sensor 51 are configured to adjust the composition of the air in the target space cooled by the refrigeration device 10.

[0066] The heat exchange section 88 is arranged to contact the evaporator 24 in the refrigerant circuit 20 of the refrigeration device 10.

[0067] In the thirteenth aspect, by setting the heat exchange section 88 to contact the evaporator 24, the cold energy of the evaporator 24 is transferred to the heat exchange section 88, the external air in the second passage 76 is cooled, and the generated moisture is removed by the moisture removal section 84.

[0068] The fourteenth aspect of this disclosure is, based on the twelfth or thirteenth aspect, characterized in that:

[0069] The heat exchange section 88 has fins 88b disposed on the pipe 88a of the second passage 76.

[0070] In the fourteenth aspect, by providing fins 88b on the heat exchange section 88 to efficiently cool the outside air, it is possible to increase the amount of moisture removed. Therefore, the possibility of moisture coming into contact with the sensor 51 is further suppressed.

[0071] The fifteenth aspect of this disclosure relates to a refrigeration device for transportation.

[0072] This includes components 21-24 of the refrigerant circuit 20 that performs the refrigeration cycle, and an air composition regulating unit 60 that regulates the air composition of the target space.

[0073] The air in the target space is cooled by the evaporator 24 in the refrigerant circuit 20. The transport refrigeration device is characterized in that:

[0074] The air composition regulating unit 60 is composed of an air composition regulating device from any one of the first to fourteenth aspects.

[0075] In the fifteenth aspect, in a transport refrigeration device including an air composition regulating device, it is possible to suppress contact between the sensor 51 and moisture when external air is introduced into the sensor 51.

[0076] The sixteenth aspect of this disclosure relates to a transport container.

[0077] The container includes a main body 2 for transporting fresh produce and a refrigeration unit 10, wherein the refrigeration unit 10 cools the interior of the main body 2 as the target space.

[0078] The transport container is characterized in that the refrigeration unit 10 is composed of the transport refrigeration unit described in the fifteenth aspect.

[0079] In the sixteenth aspect, in a transport container including an air composition conditioning device and a transport refrigeration device 10, it is possible to suppress the contact between the sensor 51 and moisture when external air is introduced into the sensor 51. Attached Figure Description

[0080] Figure 1This is a perspective view of the transport refrigeration device according to the first embodiment of the present invention, as viewed from the outside of the box;

[0081] Figure 2 It is shown Figure 1 A side sectional view of the simplified structure of a refrigeration unit for transportation;

[0082] Figure 3 It is shown Figure 1 A piping system diagram of the refrigerant circuit structure of a refrigeration unit for transportation;

[0083] Figure 4 It is shown Figure 1 A piping system diagram of the air circuit of the CA device for the refrigeration unit used for delivery, showing the air flow during the first operation;

[0084] Figure 5 It is shown Figure 1 A piping system diagram of the air circuit of the CA device for the refrigeration unit used for delivery, showing the air flow during the second operation;

[0085] Figure 6 It is shown Figure 1 The piping system diagram of the air circuit of the CA unit for the refrigeration unit for delivery shows the air flow during the external air introduction operation;

[0086] Figure 7 It is shown Figure 1 The piping system diagram of the air circuit of the CA device for the refrigeration unit used for delivery shows the air flow during sensor calibration operation;

[0087] Figure 8 This is a perspective view of the rear side of the housing of the transport refrigeration unit, showing the arrangement of the sensor units;

[0088] Figure 9 yes Figure 4 A magnified view of a portion of the image;

[0089] Figure 10 This is a 3D view of the sensor unit;

[0090] Figure 11 This is a three-dimensional view of the sensor unit as seen from below;

[0091] Figure 12 This is a diagram illustrating a variation of the first embodiment;

[0092] Figure 13 This is a simplified diagram showing the moisture removal section of the second embodiment;

[0093] Figure 14This is a perspective view showing the arrangement of the heat exchange section after a portion of the housing of the transport refrigeration device according to the second embodiment has been removed.

[0094] Figure 15 This is an enlarged perspective view of the transport refrigeration device after a portion of its housing has been removed, according to Modification 1 of the second embodiment, showing a modified example of the arrangement of the heat exchange section.

[0095] Figure 16 This is an enlarged perspective view of the transport refrigeration device after a portion of its housing has been removed, according to Modification 2 of the second embodiment, showing a modified example of the arrangement of the heat exchange section.

[0096] Figure 17 This is a simplified diagram showing the moisture removal section involved in Modification 3 of the second embodiment;

[0097] Figure 18 This is a piping system diagram illustrating the structure of the CA device involved in other embodiments. Detailed Implementation

[0098] First Implementation Method

[0099] Hereinafter, the first embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0100] <Overall Structure>

[0101] This embodiment relates to a transport container 1, which includes an air composition regulating device 60 for regulating the air composition of a target space. The air composition regulating device 60 includes a gas supply unit 30 and a sensor unit 50. The gas supply unit 30 includes: a delivery section for supplying air (air pump 31 described later); an air composition regulating section (first adsorption cylinder 34 and second adsorption cylinder 35 described later); and an air circuit 3 in which air is introduced into the regulating section by the delivery section and the air with regulated composition is supplied to the target space. The sensor unit 50 includes sensors 51 and 52, which are arranged in the target space and measure the air composition.

[0102] <Transport Containers>

[0103] like Figure 1 and Figure 2As shown, the transport container 1 includes a container body 2 and a transport refrigeration unit 10, which is used for maritime transport, etc. The transport refrigeration unit 10 cools the air inside the container body 2 (object space). Fresh produce (plants 15) is stored in the container in a packed state inside the container body 2. The plants 15 are, for example, fruits and vegetables such as bananas or avocados, vegetables, grains, bulbs, flowers, etc., and these plants 15 respire by absorbing oxygen (O2) from the air and releasing carbon dioxide (CO2).

[0104] The container body 2 is shaped like a slender cuboid box with an open end. The transport refrigeration unit 10 includes a housing 12, a refrigerant circuit 20, and a CA (Controlled Atmosphere System) 60. The housing 12 of the transport refrigeration unit 10 is mounted to close the open end of the container body 2.

[0105] <Refrigeration equipment for transportation>

[0106] The transport refrigeration unit 10 includes a refrigerant circuit 20 that performs a refrigeration cycle, in which the air inside the container body 2 is cooled in the evaporator 24 of the refrigerant circuit 20.

[0107] <case>

[0108] like Figure 2 As shown, the housing 12 of the transport refrigeration unit 10 includes an outer wall 12a located on the outside of the container body 2 and an inner wall 12b located on the inside of the container body 2. The outer wall 12a and the inner wall 12b are, for example, made of aluminum alloy.

[0109] The outer wall 12a is installed around the opening of the container body 2 in a manner that closes the opening end of the container body 2. The lower part of the outer wall 12a bulges inward toward the container body 2.

[0110] The inner wall 12b of the box is arranged opposite to the outer wall 12a of the box. The inner wall 12b bulges inward from the lower part of the outer wall 12a of the box. A heat insulation element 12c is provided in the space between the inner wall 12b and the outer wall 12a of the box.

[0111] In this way, the lower part of the shell 12 bulges inward toward the container body 2. As a result, an external storage space S1 is formed on the outside of the container body 2 in the lower part of the shell 12, and an internal storage space S2 is formed on the inside of the container body 2 in the upper part of the shell 12.

[0112] like Figure 1As shown, two maintenance openings 14 for maintenance are formed side by side along the width direction on the housing 12. The two maintenance openings 14 are respectively sealed by a first maintenance door 16A and a second maintenance door 16B that can be freely opened and closed.

[0113] like Figure 2 As shown, a partition 18 is arranged inside the container body 2. The partition 18 is composed of approximately rectangular plate components and is arranged opposite to the inner side of the shell 12. The partition 18 divides the container body 2 into the container space (object space) for storing the plants 15 and the container storage space S2.

[0114] An intake port 18a is formed between the upper end of the partition 18 and the top surface inside the container body 2. Air inside the container body 2 is drawn into the container storage space S2 through the intake port 18a.

[0115] A horizontally extending partition wall 13 is provided in the internal storage space S2. The partition wall 13 is installed at the upper end of the partition plate 18 and has an opening, in which the internal fan 26 (described later) is disposed. The partition wall 13 divides the internal storage space S2 into a primary space S21 on the intake side of the internal fan 26 and a secondary space S22 on the exhaust side of the internal fan 26. In this embodiment, the primary space S21 is arranged on the upper side, and the secondary space S22 is arranged on the lower side.

[0116] Inside the container body 2, a floor 19 is provided above the bottom surface of the container body 2 for placing the packed plants 15. A flow path 19a is formed between the bottom surface of the container body 2 and the floor 19. A gap is provided between the lower end of the partition 18 and the bottom surface of the container body 2, and the internal storage space S2 is connected to the flow path 19a.

[0117] On the inside of floor 19, near the main body of container 2 ( Figure 2 An air outlet 18b is formed on the right side of the container, which blows air cooled by the transport refrigeration unit 10 into the container body 2.

[0118] <Structure and Equipment Layout of Refrigerant Circuit>

[0119] like Figure 3 As shown, the refrigerant circuit 20 is a closed loop formed by connecting the components of the refrigerant circuit 20, namely the compressor 21, condenser 22, expansion valve 23 and evaporator 24, in sequence through the refrigerant pipe 20a.

[0120] An external fan 25 is installed near the condenser 22. The external fan 25 is driven by an external fan motor 25a to rotate and send air from the outside space of the container body 2 (outside air) to the condenser 22. In the condenser 22, the refrigerant that is pressurized by the compressor 21 and flows inside the condenser 22 exchanges heat with the outside air delivered to the condenser 22 by the external fan 25.

[0121] Two in-container fans 26 are installed near the evaporator 24. Driven by an in-container fan motor 26a, the in-container fans 26 draw in air from the container body 2 through the suction port 18a and blow it out onto the evaporator 24. In the evaporator 24, heat exchange occurs between the refrigerant flowing inside after being depressurized by the expansion valve 23 and the in-container air delivered to the evaporator 24 by the in-container fans 26.

[0122] like Figure 1 As shown, the compressor 21 and condenser 22 are housed in the external storage space S1. The condenser 22 is arranged in the central part of the external storage space S1 in the vertical direction, dividing the external storage space S1 into a lower first space S11 and an upper second space S12. In the first space S11, the compressor 21, the inverter box 29 housing the drive circuit, and the gas supply unit 30 of the CA device 60 are installed. This drive circuit drives the compressor 21 at a variable speed. In the second space S12, an external fan 25 and an electronic component box 17 are installed.

[0123] like Figure 2 As shown, the evaporator 24 is housed in the secondary space S22 of the internal storage space S2. Above the evaporator 24 in the internal storage space S2, the two internal fans 26 are arranged side by side along the width direction of the casing 12 (see reference). Figure 1 ).

[0124] <Air composition regulating device>

[0125] like Figures 4-7 As shown, the CA device 60 installed on the container body 2 includes a gas supply unit 30, an exhaust unit 46, a sensor unit 50, and a control unit 55. The CA device 60 regulates the oxygen and carbon dioxide concentrations of the air inside the container body 2. It should be noted that the term "concentration" used in the following description refers to "volume concentration".

[0126] <Gas Supply Unit>

[0127] The gas supply unit 30 is a unit that generates air with adjusted composition, which is then supplied to the interior of the container body 2. In this embodiment, the gas supply unit 30 is a device that generates nitrogen-rich air with a low oxygen concentration for supplying to the interior of the container body 2. In this embodiment, the gas supply unit 30 is constructed using VPSA (Vacuum Pressure Swing Adsorption). Figure 1 As shown, the gas supply unit 30 is arranged in the lower left corner of the storage space S1 outside the box.

[0128] like Figure 4 As shown, the gas supply unit 30 has an air circuit 3, to which an air pump 31, a first directional control valve 32, a second directional control valve 33, a first adsorption cylinder 34, and a second adsorption cylinder 35 are connected. Adsorbents for adsorbing nitrogen components in the air are disposed inside the first adsorption cylinder 34 and the second adsorption cylinder 35. The components of the air circuit 3 are housed in the unit housing 36.

[0129] (air pump)

[0130] The air pump 31 has a first pump mechanism (pressurizing pump mechanism) 31a that draws in air and ejects it after pressurization, and a second pump mechanism (pressure reducing pump mechanism) 31b. The first pump mechanism 31a and the second pump mechanism 31b are connected to the drive shaft of the motor 31c.

[0131] (Air circuit)

[0132] The air circuit 3 connected to the air pump 31 and other components includes an external air passage 41, a pressurization passage 42, a depressurization passage 43, and a supply passage 44.

[0133] An external air passage 41 is connected to the suction port of the first pump mechanism 31a. The external air passage 41 penetrates the unit housing 36, thus connecting the interior and exterior of the unit housing 36. A breathable and waterproof membrane filter 37 is provided at the other end of the external air passage 41. The other end of the external air passage 41 with the membrane filter 37 is located in a second space S12 above the condenser 22 in the external storage space S1, which is not shown in the figure.

[0134] One end of the pressurization passage 42 is connected to the nozzle of the first pump mechanism 31a. The other end of the pressurization passage 42 branches into two, which are connected to the first directional control valve 32 and the second directional control valve 33.

[0135] One end of a pressure-reducing passage 43 is connected to the suction port of the second pump mechanism 31b. The other end of the pressure-reducing passage 43 branches into two, connecting to the first directional control valve 32 and the second directional control valve 33. One end of a supply passage 44 is connected to the discharge port of the second pump mechanism 31b. The other end of the supply passage 44 opens into the secondary space S22 on the blowing side of the internal fan 26 within the container body 2's internal storage space S2. A check valve 65 is provided at the other end of the supply passage 44, which allows air to flow into the internal storage space S2 and prevents backflow of air.

[0136] Two air supply fans 49 are provided on the side of the air pump 31, and the two air supply fans 49 cool the air pump 31 by supplying air to the air pump 31.

[0137] The pressurization pump mechanism, i.e., the first pump mechanism 31a, performs adsorption by supplying pressurized air to one of the adsorption cylinders 34 and 35, during which nitrogen components in the pressurized air are adsorbed into the adsorbent within the adsorption cylinders 34 and 35. The depressurization pump mechanism, i.e., the second pump mechanism 31b, performs desorption (generating nitrogen-rich air) by drawing air from another adsorption cylinder 35 and 34, during which nitrogen components adsorbed into the adsorbent within the adsorption cylinders 35 and 34 are desorbed.

[0138] Supply passage 44 is the passage through which nitrogen-rich air generated during the desorption action is supplied to the container body 2 during the alternating adsorption and desorption actions in the adsorption cylinders 34 and 35.

[0139] The outlet of the pressurization passage 42 on the side of the pressurization pump mechanism 31a (between the pressurization pump mechanism 31a and the directional control valves 32 and 33) and the outlet of the supply passage 44 on the side of the depressurization pump mechanism 31b are connected by a bypass passage 47. A bypass switch valve 48 is provided on the bypass passage 47, which is opened and closed under the control of the control unit 55.

[0140] An external air inlet passage 40 is formed by an external air passage 41, a portion of a pressurization passage 42, a bypass passage 47 with a bypass switch valve 48, and a portion of a supply passage 44. The external air inlet passage 40 supplies pressurized air (composed of the same air as external air) that has passed through the pressurization pump mechanism 31a into the housing. A cooling section 40a is provided in the external air inlet passage 40, extending through the space outside the unit housing 36.

[0141] (Directional control valve)

[0142] The first directional control valve 32 and the second directional control valve 33 are installed in the air circuit 3 and are arranged between the air pump 31 and the first adsorption cylinder 34 and the second adsorption cylinder 35. The first directional control valve 32 and the second directional control valve 33 switch the connection state between the air pump 31 and the first adsorption cylinder 34 and the second adsorption cylinder 35 to two connection states (first connection state and second connection state) described later. This switching action is controlled by the control unit 55.

[0143] The first directional control valve 32 is connected to a pressurization passage 42 connected to the nozzle of the first pump mechanism 31a, a depressurization passage 43 connected to the suction port of the second pump mechanism 31b, and one end of the first adsorption cylinder 34 (the inlet during pressurization). The first directional control valve 32 is in a first state ( Figure 4 The state shown in the middle) and the second state ( Figure 5 The system switches between states shown in the diagram. In the first state, the first directional control valve 32 connects the first adsorption cylinder 34 to the outlet of the first pump mechanism 31a and disconnects the first adsorption cylinder 34 from the inlet of the second pump mechanism 31b. In the second state, the first directional control valve 32 connects the first adsorption cylinder 34 to the inlet of the second pump mechanism 31b and disconnects the first adsorption cylinder 34 from the outlet of the first pump mechanism 31a.

[0144] The second directional control valve 33 is connected to a pressurization passage 42 connected to the nozzle of the first pump mechanism 31a, a depressurization passage 43 connected to the suction port of the second pump mechanism 31b, and one end of the second suction cylinder 35. The second directional control valve 33 is in a first state ( Figure 4 The state shown in the middle) and the second state ( Figure 5 The system switches between states shown in the diagram. In the first state, the second directional control valve 33 connects the second adsorption cylinder 35 to the inlet of the second pump mechanism 31b and disconnects the second adsorption cylinder 35 from the outlet of the first pump mechanism 31a. In the second state, the second directional control valve 33 connects the second adsorption cylinder 35 to the outlet of the first pump mechanism 31a and disconnects the second adsorption cylinder 35 from the inlet of the second pump mechanism 31b.

[0145] If both the first directional control valve 32 and the second directional control valve 33 are set to the first state, then the air circuit 3 switches to the first connection state (refer to...). Figure 4 In the first connection state, the nozzle of the first pump mechanism 31a is connected to the first adsorption cylinder 34, and the inlet of the second pump mechanism 31b is connected to the second adsorption cylinder 35. In this state, the adsorption action of adsorbing nitrogen components from the outside air by the adsorbent takes place in the first adsorption cylinder 34, and the desorption action of desorbing the nitrogen components adsorbed in the adsorbent takes place in the second adsorption cylinder 35.

[0146] If both the first directional control valve 32 and the second directional control valve 33 are set to the second state, the air circuit 3 switches to the second connection state (refer to...). Figure 5 In the second connection state, the nozzle of the first pump mechanism 31a is connected to the second adsorption cylinder 35, and the suction port of the second pump mechanism 31b is connected to the first adsorption cylinder 34. In this state, adsorption occurs in the second adsorption cylinder 35, and desorption occurs in the first adsorption cylinder 34.

[0147] (Adsorption cylinder)

[0148] The first adsorption cylinder 34 and the second adsorption cylinder 35 are cylindrical components filled with adsorbent. The adsorbent filled in the first adsorption cylinder 34 and the second adsorption cylinder 35 has the following properties: it adsorbs nitrogen components under pressure and desorbs the adsorbed nitrogen components under depressurization.

[0149] The adsorbent filled in the first adsorption cylinder 34 and the second adsorption cylinder 35 is, for example, zeolite, which is a porous body with micropores. The pore size is smaller than the molecular diameter of a nitrogen molecule (3.0 Å) and larger than the molecular diameter of an oxygen molecule (2.8 Å). If zeolite with this pore size is used as an adsorbent, it can adsorb nitrogen components in the air.

[0150] In the first adsorption cylinder 34 and the second adsorption cylinder 35, if pressurized outside air is supplied from the air pump 31 to pressurize the interior of the first adsorption cylinder 34 and the second adsorption cylinder 35, the nitrogen component in the outside air will be adsorbed into the adsorbent. As a result, the nitrogen component is reduced to less than that of the outside air, thus generating oxygen-rich air with a lower nitrogen concentration and a higher oxygen concentration than the outside air. On the other hand, in the first adsorption cylinder 34 and the second adsorption cylinder 35, if air is drawn into the first adsorption cylinder 34 and the second adsorption cylinder 35 by the air pump 31 to depressurize the first adsorption cylinder 34 and the second adsorption cylinder 35, the nitrogen component adsorbed in the adsorbent will be desorbed. As a result, the nitrogen component contained is greater than that of the outside air, thus generating nitrogen-rich air with a higher nitrogen concentration and a lower oxygen concentration than the outside air. In this embodiment, for example, nitrogen-rich air with a nitrogen concentration of 92% and an oxygen concentration of 8% is generated.

[0151] One end of an oxygen discharge passage 45 is connected to the other end (the outlet during pressurization) of the first adsorption cylinder 34 and the second adsorption cylinder 35. This oxygen discharge passage 45 guides the oxygen-enriched air generated by pressurized external air to the outside of the container body 2. One end of the oxygen discharge passage 45 branches into two, which are respectively connected to the other ends of the first adsorption cylinder 34 and the second adsorption cylinder 35. The other end of the oxygen discharge passage 45 opens outside the gas supply unit 30, i.e., outside the container body 2. Check valves 61 are provided at the portion where the oxygen discharge passage 45 connects to the first adsorption cylinder 34 and at the branch portion where the oxygen discharge passage 45 connects to the second adsorption cylinder 35. These check valves 61 prevent air from flowing back from the oxygen discharge passage 45 to the first adsorption cylinder 34 and the second adsorption cylinder 35.

[0152] Midway through the oxygen exhaust passage 45, a check valve 62 and an orifice plate 63 are sequentially installed from one end to the other. The check valve 62 prevents nitrogen-enriched air from flowing back from the exhaust connection passage 71 (described later) to the first adsorption cylinder 34 and the second adsorption cylinder 35. The orifice plate 63 depressurizes the oxygen-enriched air that has flowed out of the first adsorption cylinder 34 and the second adsorption cylinder 35 before discharging it outside the chamber.

[0153] A pressure sensor 66 is installed in the oxygen discharge passage 45, which discharges oxygen-enriched air from the adsorption cylinders 34 and 35 to the outside of the chamber. The pressure sensor 66 is located between the junction point P0 of the first adsorption cylinder 34 and the second adsorption cylinder 35 and the check valve 62.

[0154] The exhaust connection passage 71 is a passage downstream of the pressure sensor 66 that connects the outlet of the pressure reducing pump mechanism 31b to the oxygen discharge passage 45. The check valve 62 is located between a first connection point P1 and a second connection point P2. The first connection point P1 is the connection point between the pressure sensor 66 and the oxygen discharge passage 45, and the second connection point P2 is the connection point between the oxygen discharge passage 45 and the exhaust connection passage 71. The check valve 62 allows air to flow from the first connection point P1 to the second connection point P2, but prevents air from flowing in the opposite direction.

[0155] (Supply and discharge switching mechanism)

[0156] A supply-discharge switching mechanism 70 is provided in the air circuit 3, which switches between gas supply and gas discharge operations. The gas supply operation is the operation of supplying nitrogen-enriched air from the first adsorption cylinder 34 and the second adsorption cylinder 35 into the container body 2. The gas discharge operation is the operation of discharging nitrogen-enriched air from the first adsorption cylinder 34 and the second adsorption cylinder 35 to the outside of the container. The supply-discharge switching mechanism 70 has an exhaust connection passage 71, an exhaust switching valve 72, and a supply switching valve 73.

[0157] One end of the exhaust connection passage 71 is connected to the supply passage 44, and the other end of the exhaust connection passage 71 is connected to the oxygen discharge passage 45. The other end of the exhaust connection passage 71 is connected to the oxygen discharge passage 45 at a position closer to the outside of the chamber than the orifice plate 63.

[0158] An exhaust switching valve 72 is installed on the exhaust connection passage 71. The exhaust switching valve 72 is composed of a solenoid valve located midway through the exhaust connection passage 71. The exhaust switching valve 72 switches between an open state and a closed state. In the open state, the exhaust switching valve 72 allows the flow of nitrogen-enriched air that has entered from the supply passage 44; in the closed state, the exhaust switching valve 72 cuts off the flow of nitrogen-enriched air. The opening and closing actions of the exhaust switching valve 72 are controlled by the control unit 55.

[0159] A supply switching valve 73 is installed on the supply passage 44 and positioned closer to the inside of the housing than the connection between the supply passage 44 and the exhaust connection passage 71. The supply switching valve 73 is a solenoid valve that switches between an open and closed state. In the open state, the solenoid valve allows air to flow into the housing; in the closed state, the solenoid valve cuts off air flow into the housing. The opening and closing of the supply switching valve 73 is controlled by a control unit 55.

[0160] <Exhaust section>

[0161] like Figure 2 , Figure 4 As shown, the exhaust unit 46 includes an exhaust passage 46a, an exhaust valve 46b, and a membrane filter 46c. The exhaust passage 46a connects the internal storage space S2 to the external space. The exhaust valve 46b is connected to the exhaust passage 46a, and the membrane filter 46c is located at the inflow end (inner end) of the exhaust passage 46a. The exhaust passage 46a extends from the inside of the housing 12 across the outside and through the housing 12. The exhaust valve 46b is located inside the exhaust passage 46a. The exhaust valve 46b is a solenoid valve that switches between an open and closed state. In the open state, the solenoid valve allows air to flow in the exhaust passage 46a; in the closed state, the solenoid valve cuts off air flow in the exhaust passage 46a. The opening and closing of the exhaust valve 46b is controlled by the control unit 55.

[0162] If the exhaust valve 46b is opened by the control unit 55 during the rotation of the fan 26 inside the box, an exhaust operation is performed, in which the air in the storage space S2 inside the box (the air inside the box) connected to the internal space is discharged to the outside of the box.

[0163] Specifically, if the fan 26 inside the box rotates, the pressure in the secondary space S22 on the exhaust side will be higher than the pressure (atmospheric pressure) in the outer space. Therefore, when the exhaust valve 46b is open, the pressure difference between the two ends of the exhaust passage 46a (the pressure difference between the outer space and the secondary space S22) is used to exhaust the air in the storage space S2 connected to the inner space (inner air) to the outer space through the exhaust passage 46a.

[0164] <Circuit Structure of Sensor Unit>

[0165] like Figure 2 , Figure 4 As shown, the sensor unit 50 is disposed in the secondary space S22 on the blowing side of the internal fan 26 in the internal storage space S2. The sensor unit 50 includes an oxygen sensor 51, a carbon dioxide sensor 52, a membrane filter 54, a first connecting pipe 56, and an exhaust pipe 57.

[0166] Oxygen sensor 51 is a galvanic cell type sensor. Carbon dioxide sensor 52 is a non-dispersive infrared (NDIR) sensor. Oxygen sensor 51 and carbon dioxide sensor 52 are connected via a first connecting pipe 56. One end of an exhaust pipe 57 is connected to carbon dioxide sensor 52, and the other end of exhaust pipe 57 opens near the intake of the internal fan 26. Oxygen sensor 51 has an intake for drawing in ambient air, and a membrane filter 54 is provided on the intake.

[0167] The secondary space S22 of the internal storage space S2 is connected to the primary space S21 via a connecting path 58 formed by a membrane filter 54, an oxygen sensor 51, a first connecting pipe 56, a carbon dioxide sensor 52, and an exhaust pipe 57. During the operation of the internal fan 26, the pressure in the primary space S21 is lower than that in the secondary space S22. Therefore, the air inside the chamber utilizes this pressure difference to flow from the secondary space S22 side to the primary space S21 side through the connecting path 58 connecting the oxygen sensor 51 and the carbon dioxide sensor 52. During the operation of the internal fan 26, the air inside the chamber passes sequentially through the oxygen sensor 51 and the carbon dioxide sensor 52 in the manner described above. The oxygen concentration of the air inside the chamber is measured by the oxygen sensor 51, and the carbon dioxide concentration of the air inside the chamber is measured by the carbon dioxide sensor 52.

[0168] A sensor circuit 80 is provided in the air circuit 3. This sensor circuit 80 is used to perform the gas supply measurement operation described later. In the gas supply measurement operation, the concentration of nitrogen-rich air generated in the first adsorption cylinder 34 and the second adsorption cylinder 35 is measured using an oxygen sensor (the sensor of this disclosure) 51. The sensor circuit 80 includes a branch pipe 81 and a gas concentration measuring switch valve 82. The sensor circuit 80 branches a portion of the air flowing in the supply passage 44 and guides this portion of air to the oxygen sensor 51. A branch switch valve 82 is provided on the branch pipe 81.

[0169] One end of the branch pipe 81 is connected to the supply passage 44, and the other end of the branch pipe 81 is connected to the oxygen sensor 51. The branch pipe 81 branches off from the supply passage 44 within the unit housing 36 and communicates with the internal space of the housing. A check valve 64 is provided at the other end of the branch pipe 81 (the part inside the housing), which allows air to flow from one end to the other and prevents air backflow.

[0170] Branch switching valve 82 is disposed inside unit housing 36. Branch switching valve 82 is composed of a solenoid valve that switches between an open state and a closed state. In the open state, the solenoid valve allows air to flow in branch pipe 81, and in the closed state, the solenoid valve cuts off air flow in branch pipe 81. The opening and closing actions of branch switching valve 82 are controlled by control unit 55.

[0171] When the air supply measurement is performed while the fan 26 inside the chamber is not running, the nitrogen-rich air generated in the gas supply unit 30 is led to the oxygen sensor 51 via the branch pipe 81, and the oxygen concentration of the nitrogen-rich air is measured in the oxygen sensor 51.

[0172] Oxygen sensor 51 introduces external air and performs calibration at a predetermined time. During the calibration process of oxygen sensor 51, as described later, external air pressurized by air pump 31 bypasses the first adsorption cylinder 34 and the second adsorption cylinder 35 and is introduced into oxygen sensor 51 through branch pipe 81.

[0173] In order to introduce external air into the oxygen sensor 51, the air circuit 3 has a first passage 75 (external air passage 41 and pressurization passage 42) and a second passage 76 (bypass passage 47 and branch pipe 81). In the first passage 75, external air is introduced into the first adsorption cylinder 34 and the second adsorption cylinder 35 by the air pump 31. The second passage 76 branches from the first passage 41 and 42 between the air pump 31 and the first adsorption cylinder 34 and the second adsorption cylinder 35 and is connected to the oxygen sensor 51.

[0174] A gas-liquid separator 85 is provided in the second passage 76. This gas-liquid separator 85 acts as a moisture removal unit 84 to remove moisture from the air introduced into the oxygen sensor 51. A third passage, namely a drain pipe 77, is connected to the gas-liquid separator 85 to discharge the moisture separated from the air.

[0175] The above describes the circuit structure when air from inside the chamber is directly drawn into the sensor unit 50 for detection. Next, the arrangement and structure when the oxygen sensor 51 and the carbon dioxide sensor 52 are placed inside the sensor housing 90 will be described.

[0176] Arrangement and structure of sensor units

[0177] Figure 8 This is a perspective view of the rear side of the housing 12 of the transport refrigeration unit 10, showing the arrangement of the sensor box 90. Figure 9 yes Figure 4 A magnified view of a portion of the configuration with sensor box 90. Figure 10 This is a 3D view of sensor box 90. Figure 11 This is a perspective view of the sensor box 90 as seen from below.

[0178] The sensor unit 50 has a sensor housing 90. The oxygen sensor 51 and the carbon dioxide sensor 52 are housed within the sensor housing 90. When the sensor unit 50 has a sensor housing 90, as... Figure 9 As shown, sensor unit 50 includes an oxygen sensor 51, a carbon dioxide sensor 52, a membrane filter 54, and an exhaust pipe 57. Sensor housing 90 has an intake port (not shown) for drawing in ambient air. Figure 10 , Figure 11 In the sensor housing 90, the inlet is located on the surface opposite to the surface where the gas-liquid separator 85 is fixed.

[0179] A membrane filter 54 is installed at the intake port of the sensor housing 90. One end of the exhaust pipe 57 is connected to the sensor housing 90. Air is drawn in from the intake port, passes through the interior of the sensor housing 90, and is discharged from the exhaust pipe 57. A branch pipe 81 is connected to the sensor housing 90 to introduce air. Other structures are the same as in the case where air from inside the housing is directly drawn into the sensor unit 50 for detection.

[0180] The gas-liquid separator 85 is positioned between the location where the second passage 76 branches off from the first passage 75 and the sensor housing 90. Here, "the location where the second passage branches off and the sensor housing" includes both the branching location itself and the sensor housing itself. In this embodiment, as... Figures 8-11 As shown, the gas-liquid separator 85 is fixed on the sensor box 90.

[0181] exist Figure 8In the sensor housing 90, a portion of the second passage 76, namely a branch pipe 81, is connected to the gas-liquid separator 85 fixed to the sensor housing 90. A drain pipe 77, connected to the gas-liquid separator 85, extends downwards from the separator to discharge moisture into a water collection tray 29, which is provided on the housing 12 to receive condensate generated in the transport refrigeration unit 10. An exhaust pipe 57 extends from the sensor housing 90 and opens at the intake side of the fan 26 inside the housing.

[0182] The second passage 76 includes a first portion 76a disposed inside the chamber space. A gas-liquid separator 85 is disposed within this first portion 76a, located inside the chamber space rather than outside. Since the gas-liquid separator 85 is fixed to the sensor housing 90, the distance from the gas-liquid separator 85 to the position (where air flows into the chamber through the first portion) L of the second passage 76 that traverses the chamber space is greater than the distance from the gas-liquid separator 85 to the sensor housing 90. In other words, with respect to the first portion 76a of the second passage 76, the length of the portion 76a1 from the position L traversing the chamber space to the gas-liquid separator 85 is longer than the length of the portion 76a2 from the gas-liquid separator 85 to the sensor housing 90. Therefore, moisture in the air flowing in the second passage 76 is removed from the vicinity of the oxygen sensor 51 in the first portion 76a.

[0183] like Figure 11 , Figure 12 As shown, the gas-liquid separator 85 has a cylindrical container 86. An inlet 86a for air to flow in, an outlet 86b for air to flow out after moisture (partial) has been removed, and a drain 86c for water separated from the air to be discharged.

[0184] A drain outlet 86c is located at the bottom of the container 86. The drain outlet 86c consists of a hole with a diameter of 1 mm to 3 mm. One end of a drain pipe 77 is connected to the drain outlet 86c. The lower end of the drain pipe 77 opens near the water receiving tray 29, discharging water into the water receiving tray 29. Figure 11 , Figure 12 The second passage 76 (branch pipe 81) and drain pipe 77 are omitted. The outlet 86b of the gas-liquid separator 85 is connected to the second connecting pipe 59, which communicates with the interior of the sensor box 90.

[0185] The sensor housing 90 has a main body 91 and a cover 92. The gas-liquid separator 85 is fixed to the cover 92 of the sensor housing 90 by a bracket 87. The sensor housing 90 is fixed to the housing 12 of the transport refrigeration unit 10 by a bracket 93.

[0186] Control Department

[0187] The control unit 55 performs control over the concentration adjustment operation, which aims to bring the oxygen and carbon dioxide concentrations of the air inside the container body 2 to the desired concentrations. Specifically, the control unit 55 controls the operation of the gas supply unit 30, the exhaust unit 46, and the sensor unit 50 based on the measurement results of the oxygen sensor 51 and the carbon dioxide sensor 52, so that the composition (oxygen and carbon dioxide concentrations) of the air inside the container body 2 reaches the desired composition (e.g., 5% oxygen concentration and 5% carbon dioxide concentration).

[0188] The control unit 55 includes, for example, a microcomputer that controls various elements of the CA device 60, and a storage medium such as a memory or disk that stores an executable control program. The detailed structure and algorithm of the control unit 55 can be any combination of hardware and software.

[0189] -Operational Actions-

[0190] <Operating Procedures of the Refrigerant Circuit>

[0191] In this embodiment, by Figure 3 The unit control unit 100 shown performs the cooling operation of the air inside the cooling container body 2.

[0192] During cooling operation, the unit control unit 100 controls the operation of the compressor 21, expansion valve 23, external fan 25, and internal fan 26 based on the measurement results of a temperature sensor (not shown) to bring the temperature of the air inside the container to the desired target temperature. In the refrigerant circuit 20, the refrigerant circulates, thus performing a vapor compression refrigeration cycle. The air inside the container body 2, guided by the internal fan 26 to the internal storage space S2, is cooled by the refrigerant flowing inside the evaporator 24 as it passes through it. The air cooled in the evaporator 24 is then blown back into the container body 2 through the underfloor flow path 19a and the outlet 18b. In this way, the air inside the container body 2 is cooled.

[0193] Operation of the gas supply unit

[0194] (Gas generation action)

[0195] In the gas supply unit 30, the first action is performed alternately and repeatedly at predetermined intervals (see reference). Figure 4 ) and the second action (refer to) Figure 5 This process generates nitrogen-rich air and oxygen-rich air. In the first operation, the first adsorption cylinder 34 is pressurized while the second adsorption cylinder 35 is depressurized. In the second operation, the first adsorption cylinder 34 is depressurized while the second adsorption cylinder 35 is pressurized. The switching between these operations is achieved by the control unit 55 operating the first directional control valve 32 and the second directional control valve 33.

[0196] First Action

[0197] In the first action, the control unit 55 switches both the first direction control valve 32 and the second direction control valve 33 to... Figure 4 The first state is shown. In this state, air circuit 3 is in a first connection state, in which the first adsorption cylinder 34 is connected to the outlet of the first pump mechanism 31a and the connection between the first adsorption cylinder 34 and the inlet of the second pump mechanism 31b is severed, and the second adsorption cylinder 35 is connected to the inlet of the second pump mechanism 31b and the connection between the second adsorption cylinder 35 and the outlet of the first pump mechanism 31a is severed. In this first connection state, external air pressurized by the first pump mechanism 31a is supplied to the first adsorption cylinder 34, while the second pump mechanism 31b draws in nitrogen-rich air from the second adsorption cylinder 35, which has a higher nitrogen concentration and a lower oxygen concentration than the external air.

[0198] Specifically, the first pump mechanism 31a draws in and pressurizes external air through the external air passage 41, and then ejects the pressurized external air (pressurized air) into the pressurization passage 42. The pressurized air ejected into the pressurization passage 42 flows within the pressurization passage 42. Then, the pressurized air is supplied to the first adsorption cylinder 34 via the pressurization passage 42.

[0199] In the manner described above, pressurized air flows into the first adsorption cylinder 34, where the nitrogen components are adsorbed by the adsorbent. In the first operation, pressurized external air is supplied to the first adsorption cylinder 34 from the first pump mechanism 31a, where the nitrogen components are adsorbed by the adsorbent, thereby generating oxygen-rich air with a lower nitrogen concentration and a higher oxygen concentration than the external air. The oxygen-rich air flows out of the first adsorption cylinder 34 into the oxygen discharge passage 45.

[0200] The second pump mechanism 31b draws air from the second adsorption cylinder 35. At this time, the nitrogen adsorbed in the adsorbent of the second adsorption cylinder 35 is drawn in along with the air by the second pump mechanism 31b and desorbed from the adsorbent. Thus, in the first operation, air inside the second adsorption cylinder 35 is drawn in by the second pump mechanism 31b, and the nitrogen adsorbed in the adsorbent is desorbed. This generates nitrogen-rich air containing nitrogen desorbed from the adsorbent, with a nitrogen concentration higher than that of the outside air and an oxygen concentration lower than that of the outside air. The nitrogen-rich air is drawn into the second pump mechanism 31b, pressurized, and then ejected into the supply passage 44.

[0201] The Second Action

[0202] In the second action, the control unit 55 switches both the first direction control valve 32 and the second direction control valve 33 to... Figure 5The second state is shown. In this state, air circuit 3 is in a second connection state, in which the first adsorption cylinder 34 is connected to the intake port of the second pump mechanism 31b and the outlet of the first pump mechanism 31a is disconnected; and the second adsorption cylinder 35 is connected to the outlet of the first pump mechanism 31a and the intake port of the second pump mechanism 31b is disconnected. In this second connection state, external air pressurized by the first pump mechanism 31a is supplied to the second adsorption cylinder 35, while the second pump mechanism 31b draws in nitrogen-rich air from the first adsorption cylinder 34.

[0203] Specifically, the first pump mechanism 31a draws in and pressurizes external air through the external air passage 41, and then ejects the pressurized external air (pressurized air) into the pressurization passage 42. The pressurized air ejected into the pressurization passage 42 flows within the pressurization passage 42. Then, similar to the first action, the pressurized air is supplied to the second adsorption cylinder 35 via the pressurization passage 42.

[0204] In the manner described above, pressurized air flows into the second adsorption cylinder 35, where the nitrogen components are adsorbed by the adsorbent. In the second operation, pressurized external air is supplied from the first pump mechanism 31a to the second adsorption cylinder 35, where the nitrogen components are adsorbed by the adsorbent, thereby generating oxygen-rich air with a lower nitrogen concentration and a higher oxygen concentration than the external air. The oxygen-rich air then flows out of the second adsorption cylinder 35 into the oxygen discharge passage 45.

[0205] The second pump mechanism 31b draws air from the first adsorption cylinder 34. At this time, the nitrogen component adsorbed in the adsorbent of the first adsorption cylinder 34 is drawn in along with the air by the second pump mechanism 31b and desorbed from the adsorbent. In this second operation, air inside the first adsorption cylinder 34 is drawn in by the second pump mechanism 31b, and the nitrogen component adsorbed in the adsorbent is desorbed. This generates nitrogen-rich air containing nitrogen desorbed from the adsorbent, with a nitrogen concentration higher than that of the outside air and an oxygen concentration lower than that of the outside air. The nitrogen-rich air is drawn into the second pump mechanism 31b, pressurized, and then ejected into the supply passage 44.

[0206] (Gas supply action / Gas discharge action)

[0207] In the gas supply unit 30, the gas supply and gas discharge switching mechanism 70 switches between gas supply and gas discharge operations. In the gas supply operation, nitrogen-rich air generated in the air circuit 3 is supplied to the container body 2. In the gas discharge operation, during the period from the start of the desorption operation until a predetermined time has elapsed, the generated oxygen-rich air is discharged instead of being supplied to the container body 2.

[0208] like Figure 4 , Figure 5 As shown, during the gas supply operation, the control unit 55 controls the exhaust switch valve 72 to the closed state and the supply switch valve 73 to the open state. In this way, the nitrogen-rich air alternately generated in the first adsorption cylinder 34 and the second adsorption cylinder 35 is supplied to the container body 2 through the supply passage 44, and the oxygen-rich air is discharged to the outside of the container through the oxygen discharge passage 45.

[0209] During the gas discharge operation, the control unit 55 controls the exhaust switch valve 72 to the open state and the supply switch valve 73 to the closed state (illustration omitted). In this way, nitrogen-rich air, alternately generated in the first adsorption cylinder 34 and the second adsorption cylinder 35 and ejected into the supply passage 44, flows from the exhaust connection passage 71 into the oxygen discharge passage 45, and is discharged outside the chamber together with the oxygen-rich air flowing in the oxygen discharge passage 45.

[0210] (External air introduction action)

[0211] In this embodiment, the action of introducing external air into the container body 2 can also be performed. Figure 6 In the external air introduction operation shown, the first directional control valve 32 is set to the first state, the second directional control valve 33 is set to the second state, and the bypass switch valve 48 is opened. The air supply switch valve 73 is opened, and the branch switch valve 82 is closed. If the air pump 31 is started in this state, external air flows in the external air introduction passage 40, which is composed of an external air passage 41, a part of a pressurization passage 42, a bypass passage 47, and a part of a supply passage 44, and is indicated by a thick solid line. This is because the passage resistance of the external air introduction passage 40 is smaller than the passage resistance of the flow paths through the directional switching valves 32 and 33 and the suction cylinders 34 and 35. Then, the air that is the same as the external air flowing in the external air introduction passage 40 is forced into the container body 2.

[0212] <Concentration Regulation and Operation of CA Device>

[0213] In this embodiment, the CA device 60 uses the control unit 55 to perform concentration adjustment operation, during which the composition (oxygen concentration and carbon dioxide concentration) of the air inside the container body 2 is adjusted to a desired composition (e.g., 5% oxygen concentration and 5% carbon dioxide concentration). During the concentration adjustment operation, the operation of the gas supply unit 30 and the exhaust unit 46 is controlled according to the measurement results of the oxygen sensor 51 and the carbon dioxide sensor 52, so that the composition of the air inside the container body 2 reaches the desired composition.

[0214] During concentration regulation operation, the control unit 55 keeps the gas concentration measuring switch valve 82 in the closed state. During concentration regulation operation, the control unit 55 also communicates with the unit control unit 100, which uses the unit control unit 100 to rotate the chamber fan 26. In this way, air inside the chamber is supplied to the oxygen sensor 51 and the carbon dioxide sensor 52 via the chamber fan 26, measuring the oxygen and carbon dioxide concentrations of the air inside the chamber, respectively.

[0215] During concentration regulation operation, the first and second actions are alternately and repeatedly performed to supply gas and regulate the oxygen concentration inside the container. At this time, the exhaust valve 46b of the exhaust unit 46 is opened, venting an amount of air from inside the container to the outside, equivalent to the amount of nitrogen-enriched air supplied to the container body 2 through the gas supply operation. If the oxygen concentration inside the container drops to a predetermined value (e.g., 8%), the control unit 55 stops the operation of the gas supply unit 30 to cease the gas supply operation and closes the exhaust valve 46b to stop the exhaust operation. Inside the container body 2, the plants 15 respire, thus reducing the oxygen concentration inside the container body 2, which soon reaches the target oxygen concentration of 5%.

[0216] The system can increase the oxygen concentration inside the container by introducing external air. During this external air introduction, the bypass valve 48 is opened, allowing external air drawn in by the air pump 31 to bypass the first adsorption cylinder 34 and the second adsorption cylinder 35 and be supplied to the container body 2. At this time, since the external air passes through the cooling section 40a, the temperature rise of the air inside the container is suppressed.

[0217] The oxygen concentration (and carbon dioxide concentration) of the air inside the chamber can also be adjusted by appropriately switching the gas supply, gas exhaust, and external air introduction actions; detailed explanations are omitted here.

[0218] (Gas supply measurement action)

[0219] In this embodiment, a gas supply measurement operation can be performed according to instructions from the user or periodically (e.g., every 10 days), during which the oxygen concentration of the nitrogen-rich air generated in the gas supply unit 30 is measured. The gas supply measurement operation is performed in parallel with the operation when the fan 26 inside the chamber stops rotating during the gas supply operations such as concentration adjustment operation and trial operation.

[0220] During the gas supply operation, the control unit 55 controls the branch switch valve 82 to the open state and the supply switch valve 73 to the closed state. This ensures that all the nitrogen-enriched air flowing in the supply passage 44 flows into the branch pipe 81. The nitrogen-enriched air that has flowed into the branch pipe 81 is then introduced into the oxygen sensor 51 to measure the oxygen concentration.

[0221] In this way, by measuring the oxygen concentration of the nitrogen-rich air generated in the gas supply unit 30, it is possible to confirm whether the composition (oxygen concentration, nitrogen concentration) of the nitrogen-rich air generated in the gas supply unit 30 is in the desired state.

[0222] (Sensor calibration action)

[0223] In this embodiment, it is possible to perform Figure 7 The sensor calibration operation shown involves introducing external air into the sensor unit 50 to calibrate the oxygen sensor 51. The sensor calibration operation can be performed, for example, for a short period (approximately 10 minutes) while the chamber is being cooled and concentration regulation is temporarily suspended, before resuming concentration regulation operation.

[0224] During sensor calibration, the first directional control valve 32 is set to the first state, the second directional control valve 33 is set to the second state, and the bypass switch valve 48 is opened. The air supply switch valve 73 is closed, and the branch switch valve 82 is opened. If the air pump 31 is started in this state, outside air flows through the first passage 75 and the second passage 76 and is introduced into the sensor unit 50. The oxygen sensor 51 is calibrated so that its detected value represents the oxygen concentration of the outside air.

[0225] During the sensor calibration operation, outside air passes through the gas-liquid separator 85. Therefore, at least a portion of the outside air, having had its moisture removed, comes into contact with the oxygen sensor 51.

[0226] -Effects of the first implementation method-

[0227] In this first embodiment, since a gas-liquid separator 85 is provided in the second passage 76 branching off from the first passage 75, when external air is introduced into the oxygen sensor 51 in the sensor housing 90, the moisture in the external air is removed in the second passage 76.

[0228] Here, when the gas-liquid separator 85 is installed in the first passage 75, moisture may be generated in the outside air flowing in the second passage 76 after passing through the gas-liquid separator 85, which may cause the oxygen sensor 51 to malfunction. In this embodiment, since the moisture in the outside air is removed by the second passage 76 instead of the first passage 75, the effect of preventing moisture from contacting the oxygen sensor 51 can be improved, thereby preventing the oxygen sensor 51 from malfunctioning.

[0229] In the first embodiment, the gas-liquid separator 85 is arranged between the portion of the second passage branching off from the first passage and the sensor housing 90 that houses the oxygen sensor 51. Therefore, at least a portion of the moisture in the outside air is removed by the gas-liquid separator 85 before the outside air flows into the sensor housing 90.

[0230] Here, the temperature inside the chamber is lower than the temperature outside the chamber. Due to the temperature change from the outside to the inside of the chamber, moisture is generated in the outside air introduced to the oxygen sensor 51. In this embodiment, since the gas-liquid separator 85 is arranged in the first portion 76a of the second passage 76, the moisture in the outside air is removed in the first portion 76a on the chamber side, i.e., near the oxygen sensor 51. Therefore, the possibility of moisture coming into contact with the oxygen sensor 51 can be further suppressed.

[0231] In particular, in this embodiment, the length of the first portion 76a of the second passage 76 from the inlet portion where air enters the chamber space to the gas-liquid separator 85 is longer than the length from the gas-liquid separator 85 to the sensor housing 90, and the gas-liquid separator 85 is arranged near the sensor housing 90. Therefore, even if the gas-liquid separator 85 is located outside the sensor housing 90, moisture in the external air introduced into the oxygen sensor 51 can be removed near the oxygen sensor 51.

[0232] In this embodiment, since the drain outlet 86c of the gas-liquid separator 85 is located at the lower part of the container 86, external air flows into the gas-liquid separator 85 from the upper inlet 86a, and moisture flows out from the lower drain outlet 86c. Therefore, moisture is easily separated from the external air, and the moisture separated in the gas-liquid separator 85 is easily discharged by its own weight.

[0233] Furthermore, in this embodiment, the drain outlet 86c is formed by a hole with a diameter of 1 mm to 3 mm. If the diameter of the drain outlet 86c is less than 1 mm, water is difficult to drain from the gas-liquid separator 85 due to surface tension. If the amount of water flowing out of the gas-liquid separator 85 decreases, it becomes difficult for external air to be introduced into the gas-liquid separator 85, which in turn hinders the introduction of external air into the sensor 51, making calibration difficult. Therefore, in this embodiment, the diameter of the drain outlet 86c is 1 mm or more. If the diameter of the drain outlet 86c is greater than 3 mm, the flow rate of external air flowing out of the drain outlet 86c increases, making it difficult for external air to be introduced into the oxygen sensor 51 inside the sensor housing 90. Moreover, if the flow rate of external air flowing into the sensor housing 90 decreases, it becomes difficult for the oxygen concentration inside the sensor housing 90 to change from the concentration inside the housing to the concentration of external air, and the time required for calibration of the oxygen sensor 51 will increase. Therefore, in this embodiment, the diameter of the drain outlet 86c is 3 mm or less. In this embodiment, by making the diameter of the drain outlet 86c 1 mm or more and 3 mm or less, an amount of water suitable for calibrating the oxygen sensor 51 can be discharged.

[0234] In this embodiment, the gas-liquid separator 85 is fixed to the sensor housing 90, which houses the oxygen sensor 51. This structure allows for the removal of moisture from the external air introduced into the oxygen sensor 51 from outside the sensor housing 90, near the oxygen sensor 51, and also simplifies the structure for achieving this purpose.

[0235] In this embodiment, the moisture in the outside air separated in the gas-liquid separator 85 is discharged to the water collection tray 29 of the transport refrigeration unit 10. With this structure, the water collection tray 29 originally installed on the transport refrigeration unit 10 can be used, thus eliminating the need for a dedicated moisture discharge structure. Therefore, the structure of the air composition regulating device 60 can be simplified.

[0236] - Variations of the first embodiment -

[0237] (Variation Example 1)

[0238] The gas-liquid separator 85 may also not be located outside the sensor housing 90, but rather as... Figure 12 The gas-liquid separator 85 can be arranged inside the sensor housing 90 as shown. Alternatively, a water-capturing filter can be arranged inside the sensor housing 90 as a water removal unit 84, replacing the gas-liquid separator 85.

[0239] In this modified example, moisture in the outside air is removed inside the sensor housing 90. Therefore, in this modified example, compared to the case where the moisture removal unit 84 is arranged outside the sensor housing 90, moisture in the outside air can be removed at a position closer to the oxygen sensor 51. As a result, after passing through the gas-liquid separator 85, virtually no moisture is generated in the outside air, further improving the effect of suppressing moisture from contacting the oxygen sensor 51.

[0240] (Variation Example 2)

[0241] In the first embodiment, the inlet 86a of the gas-liquid separator 85 is located on the side of the container 86, and the outlet 86b is located on the top. Alternatively, the inlet 86a may be located on the top of the container 86, and the outlet 86b may be located on the side, but this is not shown in the figure.

[0242] Second Implementation Method

[0243] The second embodiment is an example of not using the gas-liquid separator 85 of the first embodiment, but using a portion of the branch pipe 81 as a moisture removal unit 84.

[0244] Figure 13This is a simplified diagram showing the moisture removal unit 84 according to the second embodiment. The moisture removal unit 84 is constituted by a heat exchange unit 88, which is a portion of the branch pipe 81 of the second passage 76. The heat exchange unit 88 is provided for cooling the air flowing in the branch pipe 81 of the second passage 76. A drain passage 89 extending downward from the second passage 76 is connected to the heat exchange unit 88. The drain passage 89 may also be connected to the second passage 76 at a position further downstream in the airflow direction than the heat exchange unit 88. The drain passage 89 is configured to discharge water to the water collection tray 29 in the same manner as the drain pipe 77.

[0245] Figure 14 This is a perspective view showing the state after a portion of the housing 12 of the transport refrigeration unit 10 has been removed, illustrating the specific arrangement of the heat exchange section 88. For example... Figure 14 As shown, the second passage 76 is arranged to contact the evaporator 24 of the transport refrigeration unit 10, and the portion arranged along the evaporator 24 constitutes a heat exchange section 88. Specifically, the heat exchange section 88 is arranged along the heat transfer tubes of the evaporator 24.

[0246] The other structures of this second embodiment are the same as those of the first embodiment. Therefore, the description of the other structures is omitted.

[0247] In this second embodiment, in the evaporator 24, the refrigerant flowing inside the heat transfer tubes absorbs heat from the air surrounding the evaporator 24, thus cooling the air. At this time, the heat exchange section 88 arranged along the heat transfer tubes is also cooled. Therefore, the external air flowing inside the heat exchange section 88 is also cooled, and moisture liquefies inside the heat exchange section 88. Since a downwardly extending drain path 89 is connected to the branch pipe 81, the generated moisture is discharged from the drain path 89 by its own weight.

[0248] According to this second embodiment, the external air flowing in the heat exchange section 88 is cooled by the refrigerant flowing in the evaporator 24, and the generated moisture is discharged from the drain passage 89. As a result, the external air introduced into the oxygen sensor 51 becomes air with moisture (partially) removed, thereby suppressing contact between the oxygen sensor 51 and moisture. Therefore, it is possible to suppress the malfunction of the oxygen sensor 51 caused by moisture.

[0249] -Modifications of the Second Embodiment-

[0250] (Variation Example 1)

[0251] Figure 15 A variation 1 of the second embodiment is shown. In this variation 1, the arrangement of the heat exchange section 88 is the same as... Figure 14 The second implementation method is different.

[0252] In this modified example 1, the heat exchange section 88 is arranged along a manifold, and the heat transfer tube of the evaporator 24 is connected to the manifold. Even with the above configuration, the external air flowing in the heat exchange section 88 is cooled by the evaporator 24, and the resulting moisture is discharged from the drain passage 89. Therefore, since the external air introduced into the oxygen sensor 51 is air that has been dehydrated (partially), it is possible to suppress the malfunction of the oxygen sensor 51.

[0253] The heat exchange section 88 can also be arranged along a tube sheet with fixed heat transfer tubes (not shown), instead of along a manifold.

[0254] (Variation Example 2)

[0255] Figure 16 A variation 2 of the second embodiment is shown. In this variation, the arrangement of the heat exchange section 88 is the same as... Figure 14 The second implementation method and Figure 15 The variation is different from Example 1.

[0256] In this modified example 2, the heat exchange section 88 is arranged along the branch pipe of the evaporator 24. Even with the above configuration, the external air flowing in the heat exchange section 88 is cooled by the evaporator 24, and the resulting moisture is discharged from the drain passage 89. Therefore, since the external air introduced into the oxygen sensor 51 is air that has been dehydrated (partially), it is possible to suppress the malfunction of the oxygen sensor 51.

[0257] (Variation Example 3)

[0258] Figure 17 A variation 3 of the second embodiment is shown. In this variation, the structure and arrangement of the heat exchange section 88 are the same as... Figures 14-16 The structures shown are different.

[0259] In this variation 3, the heat exchange section 88 has a pipe 88a of a second passage 76 (branch pipe 81) and a plurality of fins 88b disposed on the pipe 88a. The heat exchange section 88 is arranged in a secondary space S22 of the internal storage space S2, which is a flow path for air cooled by the transport refrigeration unit 10. The heat exchange section 88 is composed of at least a portion of the second passage 76 from the portion entering the internal space to the heat exchange section 88.

[0260] In this modified example 3, air cooled by the evaporator 24 in the transport refrigeration unit 10 passes around the heat exchange section 88. This cools the external air flowing inside the heat exchange section 88, and the resulting moisture in the external air is discharged through the drain passage 89. Therefore, since the external air introduced into the oxygen sensor 51 is partially dehydrated, malfunction of the oxygen sensor 51 can be prevented. In this structure, the external air is efficiently cooled because fins 88b are provided on the heat exchange section 88.

[0261] (Variation Example 4)

[0262] In the above-described variation 3, fins 88b are provided on the heat exchange section 88, but fins 88b may not be provided (not shown).

[0263] With the configuration described above, compared to a structure that does not arrange the moisture removal unit 84, i.e., the heat exchange unit 88, in the second passage 76, the moisture in the external air introduced into the oxygen sensor 51 can be reduced. Therefore, it is possible to suppress the malfunction of the oxygen sensor 51.

[0264] Other Implementation Methods

[0265] The above implementation method can also adopt the following structure.

[0266] In the above embodiment, the second passage 76, branching from the first passage 75, is formed by the bypass passage 47 and the branch pipe 81, but other structures are also possible. For example, Figure 18 As shown, alternatively, one end of the bypass passage 78, arranged parallel to the first adsorption cylinder 34, can be connected to the pressurization passage 42, and the other end of the bypass passage 78 can be connected to the oxygen discharge passage 45. In this configuration, external air flows sequentially through the bypass passage 78 with the bypass switch valve 78a, the oxygen discharge passage 45, the exhaust connection passage 71, the supply passage 44, and the branch pipe 81, thereby enabling the introduction of external air into the oxygen sensor 51 during calibration. Thus, the second passage 76 can simply be a branch from the first passage that can introduce external air into the oxygen sensor 51; it can also be a passage that branches off from and merges with the first passage 75.

[0267] In the above embodiment, oxygen sensor 51 was described as the target sensor for inhibiting contact with moisture, but the target sensor is not limited to oxygen sensor 51. The target sensor can be any sensor that measures the concentration of components in the air inside the chamber. For example, carbon dioxide sensor 52 could be used instead of oxygen sensor 51, or carbon dioxide sensor 52 could be used in addition to oxygen sensor 51. The target sensor could also be an ethylene sensor that detects ethylene concentration, or a leak detection sensor that detects refrigerant leakage into the chamber. In structures using other sensors, if the sensor might malfunction due to moisture, that sensor could also be used as the target.

[0268] In the above embodiment, an air pump 31 is used with a structure having a first pump mechanism 31a and a second pump mechanism 31b, but the first pump mechanism 31a and the second pump mechanism 31b can also be composed of two separate air pumps.

[0269] The conveying section of the above-described embodiment can also be constructed using an air supply mechanism.

[0270] In the above embodiments, one adsorption cylinder is used for nitrogen adsorption and desorption as the first adsorption section and the second adsorption section, respectively. However, the number of adsorption cylinders constituting each adsorption section is not limited to one. For example, each adsorption section may consist of three adsorption cylinders, and a total of six adsorption cylinders may be used.

[0271] The adjustment units 34 and 35 in the above embodiments are not limited to structures using adsorbents such as zeolite. For example, they may also be structures that use gas separation membranes with different nitrogen and oxygen (and carbon dioxide) permeability to generate nitrogen-rich air and oxygen-rich air, and use these nitrogen-rich air and oxygen-rich air to adjust the composition of the air in the chamber.

[0272] In the above embodiments, examples of applying the CA device 60 according to the present invention to a transport refrigeration device 10 installed on the main body 2 of a maritime transport container have been described, but the application of the CA device 60 according to the present invention is not limited thereto. In addition to being able to adjust the composition of the air inside a maritime transport container, the CA device 60 according to the present invention can also be used to adjust the composition of the air inside, for example, a land transport container, a simple refrigerated warehouse, or a room temperature warehouse.

[0273] The above describes the embodiments and modifications, but it is understood that various changes can be made to the scheme and specific circumstances without departing from the spirit and scope of the claims. The above embodiments and modifications can also be appropriately combined or substituted as long as the function of the object of this disclosure is not affected.

[0274] -Industry Applicability-

[0275] In summary, this disclosure is useful for air composition conditioning devices, refrigeration devices for transportation, and containers for transportation.

[0276] - Symbol Explanation -

[0277] 1. Transport containers

[0278] 2. Container body

[0279] 3. Air circuit

[0280] 10. Refrigeration equipment for transportation (refrigeration unit)

[0281] 20 Refrigerant Circuit

[0282] 21. Compressor (component)

[0283] 22. Condenser (Component)

[0284] 23. Expansion valve (component)

[0285] 24. Evaporator (Components)

[0286] 29 Water Receiving Tray

[0287] 31. Air pump (transfer section)

[0288] 34 First Adsorption Cylinder (Adjustment Section)

[0289] 35 Second Adsorption Cylinder (Adjustment Section)

[0290] 51 Oxygen sensor (sensor)

[0291] 60. Air composition regulating device (air composition regulating unit)

[0292] 75 First Pathway

[0293] 76 Second Pathway

[0294] 76a Part 1

[0295] 77 Third Pathway

[0296] 85 Gas-liquid separator (moisture removal section)

[0297] 86 containers

[0298] 86a Inlet

[0299] 86b Outlet

[0300] 86c drain outlet

[0301] 88 Heat Exchange Section (Moisture Removal Section)

[0302] 88a pipe

[0303] 88b fins

[0304] 89 Drainage Channel

[0305] 90 Sensor Box

Claims

1. An air composition regulating device, comprising: Conveying section (31), which conveys air; Adjustment units (34, 35) adjust the composition of the air; Air circuit (3), in which air is introduced into the regulating unit (34, 35) by means of the conveying unit (31), and the regulated air is supplied to the object space; as well as Sensor (51), said sensor (51) is arranged in the object space and measures the composition of air, The air composition regulating device is characterized in that: The air circuit (3) includes a first passage (75) and a second passage (76). The first passage (75) introduces external air into the regulating section (34, 35) via the delivery section (31). The second passage (76) branches off from the first passage (75) between the delivery section (31) and the regulating section (34, 35) and introduces external air into the sensor (51). A moisture removal section (84) is provided in the second passage (76) to remove moisture from the air introduced into the sensor (51).

2. The air composition regulating device according to claim 1, characterized in that: The air composition regulating device includes a sensor housing (90), and the sensor (51) is housed inside the sensor housing (90). The moisture removal unit (84) is arranged between the branch portion of the second passage (76) branching off from the first passage (75) and the sensor box (90).

3. The air composition regulating device according to claim 1, characterized in that: The air composition regulating device includes a sensor housing (90), and the sensor (51) is housed inside the sensor housing (90). The moisture removal unit (84) is arranged inside the sensor box (90).

4. The air composition regulating device according to any one of claims 1 to 3, characterized in that: The second passage (76) includes a first portion (76a) arranged inside the object space. The moisture removal unit (84) is arranged in the first part (76a).

5. The air composition regulating device according to claim 1, characterized in that: The air composition regulating device includes a sensor housing (90), and the sensor (51) is housed inside the sensor housing (90). The second passage (76) includes a first portion (76a) arranged inside the object space. The moisture removal section (84) is arranged in the first part (76a). The length of the first part (76a) of the second passage (76) from the inlet portion where air enters the object space to the moisture removal section (84) is longer than the length from the moisture removal section (84) to the sensor box (90).

6. The air composition regulating device according to claim 4, characterized in that: The conveying unit (31), the regulating unit (34, 35), the air circuit (3), and the sensor (51) are configured to regulate the composition of the air in the object space cooled by the refrigeration device (10). At least a portion of the first part (76a) of the second passage (76), from the inlet portion where air enters the object space to the moisture removal section (84), is arranged in the flow path of the air cooled by the refrigeration device (10).

7. The air composition regulating device according to any one of claims 1 to 3, characterized in that: The moisture removal unit (84) is composed of a gas-liquid separator (85), which includes a container (86) having an inlet (86a) for air to flow in, an outlet (86b) for gas to flow out after moisture is separated from the air, and a drain (86c) for water to be discharged from the air.

8. The air composition regulating device according to claim 7, characterized in that: The drain outlet (86c) is located at the bottom of the container (86).

9. The air composition regulating device according to claim 8, characterized in that: The drain outlet (86c) is composed of holes with a diameter of more than 1 mm and less than 3 mm.

10. The air composition regulating device according to claim 1, characterized in that: The air composition regulating device includes a sensor housing (90), and the sensor (51) is housed inside the sensor housing (90). The moisture removal unit (84) is composed of a gas-liquid separator (85), which includes a container (86) having an inlet (86a) for air to flow in, an outlet (86b) for gas from which moisture is separated from the air to flow out, and a drain (86c) for discharging the moisture separated from the air. The gas-liquid separator (85) is fixed on the sensor box (90).

11. The air composition regulating device according to claim 7, characterized in that: The conveying unit (31), the regulating unit (34, 35), the air circuit (3), and the sensor (51) are configured to regulate the composition of the air in the object space cooled by the refrigeration device (10). The third passage (77) through which the water separated by the gas-liquid separator (85) is discharged is connected to the drain outlet (86c). The third passage (77) is configured to discharge water to a water receiving tray (29), which receives condensate generated in the refrigeration device (10).

12. The air composition regulating device according to any one of claims 1 to 3, characterized in that: The moisture removal section (84) includes a heat exchange section (88) and a drainage path (89). The heat exchange section (88) cools the air flowing in the second passage (76), and the drainage path (89) extends downward from the second passage (76) at a position on the downstream side of the heat exchange section (88) or closer to the air flow direction than the heat exchange section (88).

13. The air composition regulating device according to claim 12, characterized in that: The conveying unit (31), the regulating unit (34, 35), the air circuit (3), and the sensor (51) are configured to regulate the composition of the air in the object space cooled by the refrigeration device (10). The heat exchange section (88) is arranged to contact the evaporator (24) in the refrigerant circuit (20) of the refrigeration device (10).

14. The air composition regulating device according to claim 12, characterized in that: The heat exchange section (88) has fins (88b) disposed on the pipe (88a) of the second passage (76).

15. A refrigeration device for transportation, comprising components (21-24) of a refrigerant circuit (20) for performing a refrigeration cycle, and an air composition regulating unit (60) for regulating the composition of air in the target space. The air in the object space is cooled by the evaporator (24) in the refrigerant circuit (20). The transport refrigeration device is characterized in that: The air composition regulating unit (60) is constituted by the air composition regulating device according to any one of claims 1 to 14.

16. A transport container, comprising a container body (2) for transporting fresh goods and a refrigeration unit (10), wherein the refrigeration unit (10) cools the interior of the container body (2) as the target space, the transport container being characterized in that: The refrigeration device (10) is composed of the transport refrigeration device as described in claim 15.

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