Air composition adjusting device, refrigeration device, and transport container

Abstract

In the air composition adjusting device (60), a cover unit (100) is provided, which includes a cover (101) covering the periphery of the gas sensor (51), an inflow path (111) introducing air into the cover (101), and an outflow path (112) discharging air in the cover (101).

Description

Technical Field

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

[0002] To date, air composition regulating devices that adjust the oxygen or carbon dioxide concentration in the interior space of transport containers have used gas sensors that measure the composition of air (see, for example, Patent Document 1). In such air composition regulating devices, the concentration of oxygen or carbon dioxide in the interior space is measured using a gas sensor while the concentration is controlled within an appropriate range.

[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] However, gas sensors can deteriorate due to corrosive components in the air flowing in from outside or inside the enclosure. Corrosive components are gases containing substances that corrode materials, such as sulfur, phosphorus, calcium, chlorine, and ammonia.

[0008] The purpose of this disclosure is to suppress the degradation of gas sensors used to measure the composition of air.

[0009] - Technical solutions for solving technical problems -

[0010] The first aspect of this disclosure relates to an air composition regulating device, which includes a conveying unit 31, regulating units 34 and 35, an air circuit 3, a gas sensor 51, and a cover unit 100. The conveying unit 31 conveys air, and the regulating units 34 and 35 regulate the composition of air in an object space. In the air circuit 3, the conveying unit 31 introduces air into the regulating units 34 and 35 and supplies the air with regulated composition to the object space. The gas sensor 51 is arranged in the object space and measures the composition of the air. The cover unit 100 includes a cover 101 covering the gas sensor 51, an inflow path 111 that introduces air into the cover 101, and an outflow path 112 that allows air to flow out of the cover 101.

[0011] In the first aspect, by covering the gas sensor 51 with a cover 101, contact between the gas sensor 51 and corrosive components in the air is suppressed, thereby suppressing the deterioration of the gas sensor 51.

[0012] Secondly, based on the first aspect, the inner diameter of the inflow path 111 and the inner diameter of the outflow path 112 are 1 mm or more and 4 mm or less.

[0013] If the inner diameters of the outflow path 112 and the inflow path 111 are too small, the responsiveness of the gas sensor 51 will deteriorate. If the inner diameters of the outflow path 112 and the inflow path 111 are too large, the time or frequency of contact between the gas sensor 51 and corrosive components will increase, and the gas sensor 51 will be prone to degradation. By making the inner diameters of the outflow path 112 and the inflow path 111 between 1 mm and 4 mm, the responsiveness of the gas sensor 51 can be ensured and the degradation of the gas sensor 51 can be suppressed.

[0014] Thirdly, based on the first or second aspect, the outflow path 112 is located on the upper part of the cover 101.

[0015] In the third aspect, the heat from the gas sensor 51 and the like can be discharged from the outlet 112 at the top of the cover 101 to the outside of the cover 101. In this way, the temperature rise inside the cover 101 can be suppressed.

[0016] The fourth aspect is based on any one of the first to third aspects, wherein the inflow path 111 is located at the lower part of the cover 101.

[0017] In the fourth aspect, water inside the cover 101 can be discharged to the outside of the cover 101 through the inflow passage 111 at the bottom of the cover 101.

[0018] The fifth aspect is based on any one of the first to fourth aspects, wherein the detection part 51a of the gas sensor 51 is located on a straight line connecting the inflow path 111 and the outflow path 112.

[0019] In the fifth aspect, air flowing from the inflow path 111 to the outflow path 112 can easily pass through the detection unit 51a, thus ensuring the responsiveness of the gas sensor 51.

[0020] In the sixth aspect, based on any one of the first to fifth aspects, the inflow path 111 is constituted by a first hole h1 formed in the cover 101, and the outflow path 112 is constituted by a second hole h2 formed in the cover 101.

[0021] In the sixth aspect, it is possible to reduce the flow resistance of inflow path 111 and outflow path 112.

[0022] The seventh aspect, based on any one of the first to fifth aspects, is that the inflow path 111 is constituted by a first cylindrical portion 131 connected to the cover 101, and the outflow path 112 is constituted by a second cylindrical portion 132 connected to the cover 101.

[0023] Based on any one of the first to seventh aspects, the gas sensor 51 is configured to generate heat in the on state, and the cover 101 is configured to form an airflow as the gas sensor 51 generates heat.

[0024] In the eighth aspect, an upward airflow is formed inside the cover 101 when the gas sensor 51 is turned on. In this way, air inside the cover 101 can be transported.

[0025] Based on any one of the first to eighth aspects, the ninth aspect, the air composition regulating device includes a sensor housing 90 that houses the gas sensor 51 inside, the sensor housing 90 including an inlet 94 for introducing air into the interior of the sensor housing 90, and a cover 101 disposed between the inlet 94 and the gas sensor 51.

[0026] In the ninth aspect, by using the cover 101 arranged between the inlet 94 and the gas sensor 51, it is possible to suppress corrosive components that enter the sensor housing 90 along with the air from contacting the gas sensor 51.

[0027] In the tenth aspect, based on the ninth aspect, the inlet 94 is arranged below the gas sensor 51, and the cover 101 has a portion arranged below the gas sensor 51.

[0028] In the tenth aspect, when corrosive components enter the sensor housing 90 together with air from the inlet 94 located below the gas sensor 51, the cover 101 can be used to suppress the corrosive components from reaching the gas sensor 51.

[0029] Eleventh aspect, based on the ninth aspect, the inlet 94 includes a first inlet 94a and a second inlet 94b, the first inlet 94a introducing air from inside the object space into the sensor housing 90, and the second inlet 94b introducing air from outside the object space into the sensor housing 90, at least one of the first inlet 94a and the second inlet 94b being arranged below the gas sensor 51, and the cover 101 having a portion arranged below the gas sensor 51.

[0030] In the eleventh aspect, when air from inside or outside the object space is introduced into the sensor housing 90, even if the air contains corrosive components, the cover 101 can be used to suppress the corrosive components from reaching the gas sensor 51.

[0031] Based on any one of the first to eighth aspects, the air composition regulating device includes a contact suppression unit that suppresses corrosive components in the air from contacting the gas sensor 51, and the contact suppression unit has an adsorption component 105 for adsorbing corrosive components in the air.

[0032] In the twelfth aspect, corrosive components in the air are adsorbed by the adsorption component 105, thus preventing the corrosive components from contacting the gas sensor 51.

[0033] Thirteenth aspect: Based on the twelfth aspect, the air composition regulating device includes a sensor housing 90, which houses the gas sensor 51 inside, and the adsorption component 105 is arranged inside the sensor housing 90.

[0034] In the thirteenth aspect, by using the adsorption component 105 to adsorb corrosive components in the air entering the sensor housing 90, it is possible to suppress the contact between corrosive components and the gas sensor 51.

[0035] In the fourteenth aspect, based on the twelfth aspect, the air composition regulating device includes a sensor housing 90, which houses the gas sensor 51 inside, and an inlet passage 59 for introducing air into the interior of the sensor housing 90 is connected to the sensor housing 90, with the adsorption component 105 arranged in the inlet passage 59.

[0036] In the fourteenth aspect, by providing the adsorption component 105 in the inlet path 59 that introduces air into the sensor housing 90, it is possible to suppress the contact between corrosive components and the gas sensor 51.

[0037] In the fifteenth aspect, based on the twelfth aspect, the air composition regulating device includes a sensor housing 90, which houses the gas sensor 51 inside, and has an inlet 94 for introducing air into the interior of the sensor housing 90, with the adsorption component 105 arranged at the inlet 94.

[0038] In the fifteenth aspect, by providing the adsorption component 105 at the inlet 94 of the sensor housing 90, it is possible to suppress contact between corrosive components and the gas sensor 51. The adsorption component 105 can also be provided at both the air inlet 59 (for introducing air into the sensor housing 90) and the inlet 94. With this configuration, contact between corrosive components and the gas sensor 51 can be more effectively suppressed.

[0039] The sixteenth aspect, based on the twelfth aspect, is that the adsorption component 105 is arranged in the inlet section where air flows into the air circuit 3.

[0040] In the sixteenth aspect, by providing the adsorption component 105 at the inlet where air flows into the air circuit 3, it is possible to suppress the contact between corrosive components and the gas sensor 51.

[0041] The seventeenth aspect, based on any one of aspects 12 to 16, is that the adsorption component 105 adsorbs corrosive components containing sulfur or phosphorus.

[0042] In the seventeenth aspect, it is possible to suppress the contact between corrosive components containing sulfur or phosphorus and the gas sensor 51, thereby suppressing the deterioration of the gas sensor 51.

[0043] The eighteenth aspect relates to a refrigeration apparatus comprising components 21 to 24 of a refrigerant circuit 20 that performs a refrigeration cycle, and an air composition regulating unit 60 that regulates the composition of air in a target space, wherein the air in the target space is cooled by an evaporator 24 in the refrigerant circuit 20, and the air composition regulating unit 60 is composed of an air composition regulating device according to any one of the first to seventeenth aspects.

[0044] In the eighteenth aspect, in a refrigeration device including an air composition regulating device, it is possible to suppress corrosive components from contacting the gas sensor 51, thereby suppressing the deterioration of the gas sensor 51.

[0045] The nineteenth aspect relates to a transport container, the transport container comprising a container body 2 for transporting fresh goods and a transport refrigeration device 10 for cooling the interior of the container body 2 as an object space, the transport refrigeration device 10 being composed of the refrigeration device of the eighteenth aspect.

[0046] In the nineteenth aspect, in a transport container including an air composition conditioning device and a transport refrigeration device, it is possible to suppress corrosive components from contacting the gas sensor 51, thereby suppressing the deterioration of the gas sensor 51. Attached Figure Description

[0047] Figure 1 This 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;

[0048] Figure 2 It is shown Figure 1 A side sectional view of the simplified structure of a refrigeration unit for transportation;

[0049] Figure 3 It is shown Figure 1 A piping system diagram of the refrigerant circuit structure of a refrigeration unit for transportation;

[0050] Figure 4 It is shown Figure 1A piping system diagram of the air circuit of the CA unit of the transport refrigeration unit, which shows the air flow during the first operation;

[0051] Figure 5 It is shown Figure 1 A duct system diagram of the air circuit of the CA unit of the transport refrigeration unit, which shows the air flow during the second operation;

[0052] Figure 6 It is shown Figure 1 A duct system diagram of the air circuit of the CA unit of the refrigeration unit for transportation, which shows the air flow during the external air introduction operation;

[0053] Figure 7 It is shown Figure 1 A duct system diagram of the air circuit of the CA unit of the refrigeration unit for transportation, which shows the airflow during sensor calibration.

[0054] 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;

[0055] Figure 9 This is a 3D view of the sensor unit;

[0056] Figure 10 This is a three-dimensional view showing the interior of the sensor unit;

[0057] Figure 11 This is a 3D view of the sensor unit from the back.

[0058] Figure 12 This is a three-dimensional view showing the interior of the sensor unit;

[0059] Figure 13 This is a simplified 3D diagram of the cover unit;

[0060] Figure 14 This is a diagram showing the cover unit as viewed from the top;

[0061] Figure 15 This is a sectional view of the cover unit;

[0062] Figure 16 This is a cross-sectional view of the cover unit involved in the modified example 2 of the first embodiment;

[0063] Figure 17 This is a perspective view showing the interior of the sensor housing according to the second embodiment;

[0064] Figure 18 This is a perspective view of the structure in which an adsorption component is provided at the housing cover according to the modified example 1 of the second embodiment;

[0065] Figure 19 This is a perspective view showing the interior of the sensor housing according to Modification 2 of the second embodiment;

[0066] Figure 20 This is a partial enlarged view of the air circuit of the CA device according to the second embodiment, variation 3;

[0067] Figure 21 This is a partially enlarged view of the air circuit of the CA device involved in the second embodiment, variant 4;

[0068] Figure 22 This is a piping system diagram showing the air circuit of the CA device according to the third embodiment;

[0069] Figure 23 This is a perspective view of the transport refrigeration device according to the third embodiment. Detailed Implementation

[0070] First Implementation Method

[0071] Hereinafter, the first embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0072] <Overall Structure>

[0073] 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 regulating section for regulating the air composition (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 its composition regulated 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.

[0074] <Transport Containers>

[0075] like Figure 1 and Figure 2 As 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 body 2 (object space) in a boxed state. Plants 15 include, for example, fruits and vegetables such as bananas and avocados, vegetables, grains, bulbs, flowers, etc., which respire by absorbing oxygen (O2) from the air and releasing carbon dioxide (CO2).

[0076] 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.

[0077] <Refrigeration equipment for transportation>

[0078] The transport refrigeration unit 10 includes a refrigerant circuit 20 that performs a refrigeration cycle, and the evaporator 24 in the refrigerant circuit 20 cools the air inside the container body 2.

[0079] <case>

[0080] 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 made of, for example, aluminum alloy.

[0081] 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 inside of the container body 2.

[0082] The inner wall 12b of the box is arranged opposite to the outer wall 12a of the box. The lower parts of the inner wall 12b and the outer wall 12a of the box bulge inwards. Thermal insulation material 12c is provided in the space between the inner wall 12b and the outer wall 12a of the box.

[0083] As described above, the lower part of the shell 12 bulges towards the inside of the container body 2. In this way, an external storage space S1 is formed at the lower part of the shell 12 located outside the container body 2, and an internal storage space S2 is formed at the upper part of the shell 12 located inside the container body 2.

[0084] like Figure 1 As 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 closed by a first maintenance door 16A and a second maintenance door 16B that can be freely opened and closed. A ventilation port 16D is formed on the second maintenance door 16B, which can be opened and closed by a rotating cover 16C that can be rotated relative to the central axis.

[0085] like Figure 2As 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 space (object space) containing the plants 15 inside the container body 2 and the container storage space S2.

[0086] 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.

[0087] 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 located on the intake side of the internal fan 26 and a secondary space S22 located 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.

[0088] Inside the container body 2, above the bottom surface of the container body 2, there is a base plate 19 for placing the packed plants 15. A flow path 19a is formed between the bottom surface of the container body 2 and the base plate 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.

[0089] On the inner side of the base plate 19 near the container body 2 ( Figure 2 An outlet 18b is formed at the right side of the container, which blows air cooled by the transport refrigeration unit 10 into the container body 2.

[0090] <Structure and equipment layout of the refrigerant circuit>

[0091] 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.

[0092] 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 sent to the condenser 22 by the external fan 25.

[0093] Two in-container fans 26 are installed near the evaporator 24. The in-container fans 26 are driven by in-container fan motors 26a and rotate to draw in air from inside the container body 2 through the suction port 18a and blow it out to the evaporator 24. In the evaporator 24, heat exchange occurs between the refrigerant flowing inside the evaporator 24 after being depressurized by the expansion valve 23 and the in-container air delivered to the evaporator 24 by the in-container fans 26.

[0094] 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 first space S11 located on the lower side and a second space S12 located on the upper side. 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 provided. The drive circuit drives the compressor 21 in a variable speed manner. In the second space S12, the external fan 25 and the electronic component box 17 are provided.

[0095] 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, two internal fans 26 are arranged side by side along the width direction of the casing 12 (see reference). Figure 1 ).

[0096] <Air composition regulating device>

[0097] like Figures 4-7 As shown, the CA device 60 installed in 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 concentration and carbon dioxide concentration 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".

[0098] <Gas Supply Unit>

[0099] 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 composed of a VPSA (Vacuum Pressure Swing Adsorption) device. Figure 1 As shown, the gas supply unit 30 is arranged in the lower left corner of the storage space S1 outside the box.

[0100] like Figure 4As shown, the gas supply unit 30 has an air circuit 3, in 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. Inside the first adsorption cylinder 34 and the second adsorption cylinder 35, an adsorbent for adsorbing nitrogen components in the air is disposed. The components of the air circuit 3 are housed in the unit housing 36.

[0101] (air pump)

[0102] 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 (depressurizing pump mechanism) 31b. The first pump mechanism 31a and the second pump mechanism 31b are connected to the drive shaft of the motor 31c.

[0103] (Air circuit)

[0104] The air circuit 3, which is connected to components such as the air pump 31, includes an external air passage 41, a pressurization passage 42, a depressurization passage 43, and a supply passage 44.

[0105] An external air passage 41 is connected to the suction port of the first pump mechanism 31a. This external air passage 41 penetrates the unit housing 36, thus communicating between 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 (not shown) above the condenser 22 in the external storage space S1.

[0106] One end of a 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 respectively connected to the first directional control valve 32 and the second directional control valve 33.

[0107] 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, which are respectively connected 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 located on the blowing side of the internal fan 26 in the internal storage space S2 of the container body 2. 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 air backflow.

[0108] Two exhaust fans 49 are provided on the side of the air pump 31, which cool the air pump 31 by blowing air into it.

[0109] 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.

[0110] Supply passage 44 is a passage that supplies nitrogen-rich air generated during the desorption action to the container body 2 when the adsorption and desorption actions are alternately performed in the adsorption cylinders 34 and 35.

[0111] The outlet of the pressurizing pump mechanism 31a on the pressurizing passage 42 (between the pressurizing pump mechanism 31a and the directional control valves 32 and 33) is connected to the outlet of the depressurizing pump mechanism 31b on the supply passage 44 via a bypass passage 47. A bypass switch valve 48 is provided on the bypass passage 47, and the bypass switch valve 48 is controlled by the control unit 55.

[0112] 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 on the external air inlet passage 40, extending through the external space of the unit housing 36.

[0113] (Directional control valve)

[0114] A first directional control valve 32 and a second directional control valve 33 are disposed in the air circuit 3, with the first directional control valve 32 positioned between the air pump 31 and the first adsorption cylinder 34, and the second directional control valve 33 positioned between the air pump 31 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 described later (first connection state, second connection state). This switching action is controlled by the control unit 55.

[0115] 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 5The 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.

[0116] 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.

[0117] 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.

[0118] If both the first directional control valve 32 and the second directional control valve 33 are set to the second state, then 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.

[0119] (Adsorption cylinder)

[0120] 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.

[0121] 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.

[0122] In the first adsorption cylinder 34 and the second adsorption cylinder 35, if pressurized outside air is supplied from the air pump 31, pressurizing 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 in 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 the air inside the first adsorption cylinder 34 and the second adsorption cylinder 35 is drawn by the air pump 31, depressurizing 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 in 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.

[0123] 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 of the oxygen discharge passage 45 connected to the first adsorption cylinder 34 and at the branch portion connecting the oxygen discharge passage 45 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.

[0124] Midway through the oxygen exhaust passage 45, a check valve 62 and a throttling orifice 63 are sequentially arranged from one end to the other. The check valve 62 prevents nitrogen-enriched air from flowing back through the exhaust connection passage 71 (described later) towards the first adsorption cylinder 34 and the second adsorption cylinder 35. The throttling orifice 63 depressurizes the oxygen-enriched air flowing from the first adsorption cylinder 34 and the second adsorption cylinder 35 before it is discharged outside the chamber.

[0125] 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.

[0126] 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 and prevents air from flowing in the opposite direction.

[0127] (Power supply and drainage switching mechanism)

[0128] An air 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 air supply / discharge switching mechanism 70 has an exhaust connection passage 71, an exhaust switching valve 72, and a supply switching valve 73.

[0129] 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 throttle orifice 63.

[0130] An exhaust switching valve 72 is installed in 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 nitrogen-enriched air flowing in from the supply passage 44 to pass through; in the closed state, the exhaust switching valve 72 cuts off the flow of nitrogen-enriched air. The opening and closing operation of the exhaust switching valve 72 is controlled by the control unit 55.

[0131] A supply switching valve 73 is installed in the supply passage 44 and positioned further inside 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 operation of the supply switching valve 73 is controlled by the control unit 55.

[0132] <Exhaust section>

[0133] 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 in 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 penetrates the housing 12, thus communicating between the interior and exterior of the housing 12. The exhaust valve 46b is located inside the housing of 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 the flow of air in the exhaust passage 46a. The opening and closing action of the exhaust valve 46b is controlled by the control unit 55.

[0134] 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.

[0135] 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.

[0136] <Circuit Structure of Sensor Unit>

[0137] like Figure 2 , Figure 4As shown, the sensor unit 50 is disposed in the secondary space S22 located on the exhaust side of the internal fan 26 within the internal storage space S2. The sensor unit 50 includes an oxygen sensor 51, a carbon dioxide sensor 52, a membrane filter 54, and an exhaust pipe 57. The oxygen sensor 51 and the carbon dioxide sensor 52 are housed in a sensor housing 90. The sensor housing 90 includes an inlet 94 (described later) for introducing air into the interior of the sensor housing 90. Figure 4 The membrane filter 54 is installed at the inlet 94.

[0138] The oxygen sensor 51 is a zirconia sensor. The carbon dioxide sensor 52 is a nondispersive infrared (NDIR) sensor. One end of the exhaust pipe 57 is connected to the sensor housing 90, and the other end of the exhaust pipe 57 opens near the intake of the fan 26 inside the chamber.

[0139] The secondary space S22 within the internal storage space S2 is connected to the primary space S21 via a connecting passage 58 formed by a membrane filter 54, an oxygen sensor 51, 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, under this pressure difference, air inside the chamber flows from the secondary space S22 side to the primary space S21 side through the connecting passage 58, which includes the oxygen sensor 51 and the carbon dioxide sensor 52. During the operation of the internal fan 26, the air inside the chamber passes 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 is measured by the carbon dioxide sensor 52.

[0140] 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 this 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 gas sensor of this disclosure) 51. The sensor circuit 80 includes a branch pipe 81 and a branch switching valve (a switching valve for gas concentration measurement) 82, which diverts a portion of the air flowing in the supply passage 44 and directs this portion of air to the oxygen sensor 51 and the carbon dioxide sensor 52.

[0141] 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 sensor housing 90. 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.

[0142] 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 the air flow in branch pipe 81. The opening and closing action of branch switching valve 82 is controlled by control unit 55.

[0143] 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.

[0144] In an air composition regulating device, if the sensor's measured value deviates from the actual value, the concentration regulation will become unstable. Therefore, at a specified time, external air is introduced into the gas sensor 51 for calibration (correction of the measured value). During the calibration process of the oxygen sensor 51, as described below, external air pressurized by the air pump 31 bypasses the first adsorption cylinder 34 and the second adsorption cylinder 35 and is introduced into the oxygen sensor 51 through the branch pipe 81.

[0145] 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.

[0146] To remove moisture from the air introduced into the oxygen sensor 51, a gas-liquid separator 85 is provided in the second passage 76. A drain pipe 77 is connected to the gas-liquid separator 85, which discharges the moisture separated from the air.

[0147] Next, the arrangement and structure of the sensor housing 90 will be described.

[0148] Arrangement and structure of sensor units

[0149] 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 housing 90. Figure 9 This is a magnified 3D view of the sensor housing 90. Figure 10 This is a perspective view showing the interior of the sensor housing 90, with the oxygen sensor housing unit represented by an imaginary outline. Figure 11 This is a three-dimensional view of the sensor housing 90 viewed from the back. Figure 12 This is another perspective view showing the interior of the sensor housing 90. Figure 10 In the image, the cover unit 100, which will be described in detail later, is shown in dashed lines.

[0150] As described above, oxygen sensor 51 and carbon dioxide sensor 52 are housed within sensor housing 90. Gas-liquid separator 85 is fixed to sensor housing 90. Figure 9 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 outlet (not shown) for water separated from the air to be discharged.

[0151] exist Figure 8 In the sensor housing 90, a branch pipe 81, as part of a second passage 76, is connected to the inlet 86a of the gas-liquid separator 85, which is fixed to the sensor housing 90. A drain pipe 77, connected to the gas-liquid separator 85, extends downward from the gas-liquid separator 85 to discharge water into a water collection tray 28, which is provided on the housing 12 to receive condensate generated in the transport refrigeration unit 10. An exhaust pipe 57, connected to the sensor housing 90, opens at the intake side of the internal fan 26.

[0152] The sensor housing 90 has a sensor housing body 91 and a housing cover 92. The gas-liquid separator 85 is fixed to the housing cover 92 of the sensor housing 90 using a bracket 87. The sensor housing 90 is fixed to the housing 12 of the transport refrigeration unit 10 by a bracket 93. In this embodiment, the sensor housing 90 is located in the internal storage space S2.

[0153] The sensor housing 90 includes an inlet 94 for introducing air into the interior of the sensor housing 90 and an outlet 95 for air to flow out to the outside. The inlet 94 includes a first inlet 94a and a second inlet 94b. The first inlet 94a is an opening for introducing air from outside the housing into the sensor housing 90. The second inlet 94b is an opening for introducing air from inside the housing into the sensor housing 90.

[0154] like Figure 9 , Figure 10 As shown, the first inlet 94a is located on the side of the sensor housing 90, and the first inlet 94a is connected to the branch pipe 81 (second passage 76). Figure 11 As shown, the second inlet 94b is located on the back of the sensor housing 90 and opens towards the interior space. Membrane filters 54, which allow air to pass through but not moisture, are respectively installed on the first inlet 94a and the second inlet 94b. The membrane filters 54 are disposed in the vent holes of the hexagonal fastening components. An exhaust pipe 57 is connected to the outlet 95.

[0155] The first inlet 94a and the second inlet 94b are both located below the oxygen sensor 51.

[0156] The outlet 86b of the gas-liquid separator 85 is connected to the first inlet 94a by a connecting pipe 59. The connecting pipe 59 forms a first inlet path 59a for supplying air from the air pump 31 into the sensor housing 90. The second inlet 94b for introducing air into the sensor housing 90 forms a second inlet path 59b.

[0157] <Details of the oxygen sensor in the hood unit>

[0158] The air composition conditioning device 60 includes a cover unit 100. The cover unit 100 covers the area around the oxygen sensor 51. The cover unit 100 is formed of a resin material. The cover unit 100 is a molded component of synthetic resin. The cover unit 100 prevents corrosive components in the air (such as sulfur) from contacting the oxygen sensor 51. Corrosive components may be generated by the corrugated cardboard inside the box containing plants as cargo or the wooden pallets supporting them, or may be contained in the outside air.

[0159] like Figures 13-15 As shown, the cover unit 100 has a cover 101 and a pair of mounting portions 120. It should be noted that... Figure 15 For ease of explanation, the appearance of the oxygen sensor 51 is shown, but its cross-section is not. The cover 101 is formed as a bottomed cylindrical shape. The cover 101 includes a cylindrical body 102 and a hemispherical top 103 that closes one axial end of the body 102. A storage space 104 for housing the oxygen sensor 51 is formed inside the cover 101. A pair of mounting portions 120 extend radially outward from the portion of the cover 101 near the bottom. The pair of mounting portions 120 clamp the cover 101 and are opposite to each other. Fastening components such as screws are tightened into the mounting portions 120. Thus, the cover unit 100, in this state of covering the oxygen sensor 51, is fixed to the sensor housing 90 (see reference 100). Figure 12 ).

[0160] A first flat portion 107 is formed on the lower side of the cover 101, and a second flat portion 108 is formed on the upper side of the cover 101. The first flat portion 107 and the second flat portion 108 are planar portions extending along the axial direction of the cover 101. Here, the axial direction corresponds to the direction perpendicular to the opening surface 101a of the cover 101. The first flat portion 107 and the second flat portion 108 are formed, for example, by a cut surface. The first flat portion 107 and the second flat portion 108 are approximately offset by 180° about the axis P of the cover 101. The first flat portion 107 and the second flat portion 108 respectively form walls opposite to each other. The first flat portion 107 extends from one mounting portion 120 to the middle of the top 103 of the cover 101. The second flat portion 108 extends from another mounting portion 120 to the middle of the top of the cover 101.

[0161] An inflow path 111 is formed in the first flat portion 107. The inflow path 111 is a flow path for drawing air from inside the sensor housing 90 into the cover 101. The inflow path 111 is formed by a first hole h1 formed in the first flat portion 107.

[0162] An outlet path 112 is formed in the second flat portion 108. The outlet path 112 is a flow path for allowing air inside the cover 101 to flow out to the outside. The outlet path 112 is formed by a second hole h2 formed in the second flat portion 108. The inflow path 111 and the outlet path 112 are opposite to each other across the oxygen sensor 51.

[0163] The oxygen sensor 51 has a detection section 51a, which serves as the main body of the sensor, a mesh section 51b covering the detection section 51a, a plurality of output terminals 51c connected to the detection section 51a, and a substrate 51d supporting the output terminals 51c. The mesh section 51b protects the detection section 51a and has a plurality of holes for air to pass through.

[0164] The detection unit 51a is arranged between the inflow path 111 and the outflow path 112 of the cover unit 100. For example... Figure 15 As shown, the detection unit 51a is located on the straight line X connecting the inflow path 111 and the outflow path 112. In other words, the detection unit 51a is located at a position overlapping with the inflow path 111 and the outflow path 112 in the airflow direction of the inflow path 111 and the outflow path 112. The substrate 51d also serves as a sealing member for the opening surface 101a of the sealing cover 101. A storage space 104 is defined between the cover 101 and the substrate 51d.

[0165] <Regarding the inner diameters of the outflow and inflow paths>

[0166] The inner diameter of the outlet path 112 and the inner diameter of the inlet path 111 are preferably 1 mm or more and 4 mm or less. If the inner diameter of the outlet path 112 and the inner diameter of the inlet path 111 are too small, the flow resistance of the air flowing through the shroud unit 100 will become too large. In this case, problems may sometimes occur due to a decrease in the responsiveness of the oxygen sensor 51.

[0167] Specifically, for example, during operation to regulate the oxygen concentration of the air inside the chamber (see the concentration regulation operation described later for details), the oxygen concentration of the air inside the chamber is adjusted to 5%. In this case, the oxygen concentration detected by oxygen sensor 51 is approximately 5%. On the other hand, during operation to calibrate oxygen sensor 51 from this operation (see sensor calibration operation described later for details), external air containing approximately 21% oxygen is introduced into oxygen sensor 51. If the responsiveness of oxygen sensor 51 deteriorates, the detected concentration of oxygen sensor 51 will not rise for a long time during sensor calibration, thus increasing the calibration time (e.g., more than 10 minutes). Conversely, when restarting the concentration regulation operation from sensor calibration, if the responsiveness of oxygen sensor 51 deteriorates, the detected concentration of oxygen sensor 51 will not decrease for a long time, thus delaying the restart time of concentration regulation operation and worsening the controllability of oxygen concentration.

[0168] In contrast, by making the inner diameter of the outflow path 112 and the inner diameter of the inflow path 111 1 mm or more, it is possible to suppress excessive flow resistance of the air flowing through the shroud unit 100. Therefore, the responsiveness of the oxygen sensor 51 can be ensured, thereby avoiding the aforementioned problems.

[0169] By making the inner diameters of the outflow path 112 and the inflow path 111 less than 4 mm, the flow resistance of the air flowing through the shroud unit 100 can be suppressed from becoming excessive. Therefore, it is possible to suppress excessive passage of air containing corrosive components through the oxygen sensor 51. As a result, the contact time or frequency between the oxygen sensor 51 and the corrosive components can be reduced, thereby suppressing the deterioration of the oxygen sensor 51.

[0170] In this example, the inner diameter of the outflow path 112 and the inner diameter of the inflow path 111 are both 2.5 mm. While it is preferred that the inner diameter of the outflow path 112 and the inner diameter of the inflow path 111 are the same, they can also differ by, for example, a few millimeters.

[0171] <Regarding airflow inside the cover>

[0172] The oxygen sensor 51 generates heat when it is energized and becomes switched on. Specifically, the oxygen sensor 51 is a zirconia sensor, which sometimes generates heat to approximately 450°C when energized and switched on. Therefore, when the oxygen sensor 51 is operating, an upward airflow can be formed in the housing space 104 within the housing 101. As a result, it is easy to introduce a portion of the air from the sensor housing 90 into the housing 101.

[0173] In particular, since the outlet path 112 is located at the top of the cover 101, it is easy to direct the rising airflow generated by the heat to the outlet path 112. As a result, an airflow is easily formed inside the cover 101, and the heat from the oxygen sensor 51 can be quickly released to the outside.

[0174] Control Department

[0175] The control unit 55 performs control over the concentration adjustment operation, in which the oxygen and carbon dioxide concentrations of the air inside the container body 2 are brought 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 concentration and carbon dioxide concentration) of the air inside the container body 2 reaches the desired composition (e.g., 5% oxygen concentration and 5% carbon dioxide concentration).

[0176] 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.

[0177] -Operational Actions-

[0178] <Operating Procedures of the Refrigerant Circuit>

[0179] In this embodiment, by Figure 3 The unit control unit 150 shown performs the cooling operation of the air inside the cooling container body 2.

[0180] During cooling operation, the unit control unit 150 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 by the evaporator 24 is then blown back into the container body 2 through the flow path 19a below the bottom plate and the outlet 18b. In this way, the air inside the container body 2 is cooled.

[0181] Operation of the gas supply unit

[0182] (Gas generation action)

[0183] 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 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 operating the first directional control valve 32 and the second directional control valve 33 via the control unit 55.

[0184] First Action

[0185] In the first action, the control unit 55 switches both the first directional control valve 32 and the second directional control valve 33 to... Figure 4 The first state is shown. In this state, air circuit 3 is in a first connection state, where the first adsorption cylinder 34 is connected to the outlet of the first pump mechanism 31a and disconnected from the inlet of the second pump mechanism 31b, and the second adsorption cylinder 35 is connected to the inlet of the second pump mechanism 31b and disconnected from the outlet of the first pump mechanism 31a. 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.

[0186] 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.

[0187] In the manner described above, pressurized air flows into the first adsorption cylinder 34, where the nitrogen component is adsorbed by the adsorbent. In the first operation, pressurized outside air is supplied from the first pump mechanism 31a to the first adsorption cylinder 34, where the nitrogen component is adsorbed by the adsorbent, thereby generating oxygen-rich air with a lower nitrogen concentration and a higher oxygen concentration than the outside air. The oxygen-rich air flows out from the first adsorption cylinder 34 into the oxygen discharge passage 45.

[0188] The second pump mechanism 31b draws air from the second adsorption cylinder 35. At this time, the nitrogen component adsorbed in the adsorbent of the second adsorption cylinder 35, along with the air, is drawn out of the adsorbent by the second pump mechanism 31b. As described above, in the first operation, the air inside the second adsorption cylinder 35 is drawn out by the second pump mechanism 31b, and the nitrogen component adsorbed in the adsorbent is desorbed. This generates nitrogen-rich air containing the nitrogen component 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 and, after pressurization, is ejected into the supply passage 44.

[0189] The Second Action

[0190] In the second action, the control unit 55 switches both the first directional control valve 32 and the second directional control valve 33 to... Figure 5 The 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 disconnected from the outlet of the first pump mechanism 31a, and the second adsorption cylinder 35 is connected to the outlet of the first pump mechanism 31a and disconnected from the intake port of the second pump mechanism 31b. 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 nitrogen-rich air from the first adsorption cylinder 34.

[0191] 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 second adsorption cylinder 35 via the pressurization passage 42.

[0192] 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 outside 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 outside air. The oxygen-rich air then flows from the second adsorption cylinder 35 into the oxygen discharge passage 45.

[0193] 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, along with the air, is drawn out of the adsorbent by the second pump mechanism 31b. As described above, in the second operation, the air inside the first adsorption cylinder 34 is drawn out by the second pump mechanism 31b, and the nitrogen component adsorbed in the adsorbent is desorbed. This generates nitrogen-rich air containing the nitrogen component 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 and, after pressurization, is ejected into the supply passage 44.

[0194] (Gas supply action / Gas discharge action)

[0195] 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, the nitrogen-rich air generated in the air circuit 3 is supplied to the container body 2. In the gas discharge operation, the nitrogen-rich air generated is not supplied to the container body 2 for a specified period of time from the start of the desorption operation, but is discharged instead.

[0196] like Figure 4 , Figure 5 As shown, during the gas supply operation, the control unit 55 controls the exhaust valve 72 to be closed and the supply valve 73 to be open. 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, while the oxygen-rich air is discharged to the outside of the container through the oxygen discharge passage 45.

[0197] 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, the 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.

[0198] (External air introduction action)

[0199] In this embodiment, the action of introducing external air into the container body 2 can also be performed. Figure 6In 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 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, air of the same composition as the external air flowing in the external air introduction passage 40 is pressurized into the container body 2.

[0200] <Concentration Regulation and Operation of CA Device>

[0201] 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 based on 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.

[0202] During concentration regulation operation, the control unit 55 controls the branch switch valve 82 to the closed state. During concentration regulation operation, the control unit 55 also communicates with the unit control unit 150 and uses the unit control unit 150 to rotate the chamber fan 26. Thus, air inside the chamber is supplied by the chamber fan 26 to the oxygen sensor 51 and the carbon dioxide sensor 52, which respectively measure the oxygen concentration and carbon dioxide concentration of the air inside the chamber.

[0203] 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 air from the container to the outside. The amount vented is equivalent to the amount of nitrogen-enriched air supplied to the container body 2 through the gas supply action. If the oxygen concentration inside the container drops to a specified value (e.g., 8%), the control unit 55 stops the operation of the gas supply unit 30 to cease the gas supply action and closes the exhaust valve 46b to stop the exhaust action. 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%.

[0204] 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.

[0205] 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.

[0206] (Gas supply measurement action)

[0207] 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.

[0208] 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.

[0209] As described above, 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.

[0210] (Sensor calibration action)

[0211] 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.

[0212] 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 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.

[0213] During the sensor calibration operation, outside air passes through the gas-liquid separator 85. Therefore, the outside air, with at least some moisture removed, comes into contact with the oxygen sensor 51.

[0214] (Airflow inside the sensor housing)

[0215] During normal operation, Figure 10 In this process, air from inside the chamber flows into the sensor housing 90 through the second inlet 94b. The air that has flowed in through the second inlet 94b gradually fills the sensor housing 90 and flows towards the outlet 95 (refer to path R1). At this time, the body 102 of the cover 101 is located between the second inlet 94b and the oxygen sensor 51. Moreover, since the oxygen sensor 51 is covered by the cover 101, even if the air inside the chamber contains corrosive components, contact between these corrosive components and the oxygen sensor 51 can be prevented.

[0216] During gas supply measurement and sensor calibration, Figure 10 In this configuration, air from outside the chamber flows into the sensor housing 90 through the first inlet 94a. During the air supply measurement operation, this air is composed of air regulated by the adsorption cylinders 34 and 35; during the sensor calibration operation, this air is external air that bypasses the adsorption cylinders 34 and 35. This air gradually fills the sensor housing 90 while flowing towards the outlet 95 (refer to path R2). In this case, the body 102 of the cover 101 is also located between the second inlet 94b and the oxygen sensor 51. Moreover, since the oxygen sensor 51 is covered by the cover 101, even if the air outside the chamber contains corrosive components, contact between these corrosive components and the oxygen sensor 51 can be prevented.

[0217] -Effects of the first implementation method-

[0218] The first embodiment includes a cover 101 that covers the area around the oxygen sensor 51. Therefore, the cover 101 can be used to prevent corrosive components in the air from contacting the oxygen sensor 51. As a result, deterioration of the oxygen sensor 51 can be suppressed.

[0219] By making the inner diameter of the inflow path 111 and the outflow path 112 of the shroud unit 100 1 mm or more, the flow resistance of the shroud 101 can be reduced, and the decrease in the responsiveness of the oxygen sensor 51 can be suppressed. In this way, for example, the time of sensor calibration can be shortened, or the operation can be quickly switched from sensor calibration to concentration regulation.

[0220] By making the inner diameter of the inflow path 111 and the outflow path 112 of the cover unit 100 less than 4 mm, the contact time and frequency between the oxygen sensor 51 and corrosive components can be reduced. In this way, the deterioration of the oxygen sensor 51 can be suppressed, thereby extending the service life of the oxygen sensor 51.

[0221] The outlet path 112 is located at the upper part of the cover 101. Therefore, the heat from the oxygen sensor 51 can be discharged to the outside of the cover 101, thereby preventing the temperature of the air inside the cover 101 from becoming too high. It also prevents the formation of condensation inside the cover 101 due to the high temperature air cooling down when the oxygen sensor 51 stops. Moreover, by discharging air from the upper side of the cover 101, an upward airflow generated by the heat generated by the oxygen sensor 51 can be promoted.

[0222] The inflow passage 111 is located at the lower part of the cover 101. Therefore, water inside the cover 101 can be discharged to the outside of the cover 101 by its own weight through the inflow passage 111.

[0223] The detection section 51a of the oxygen sensor 51 is located between the inflow path 111 and the outflow path 112. In this way, air can easily pass around the detection section 51a, thereby improving the responsiveness of the oxygen sensor 51.

[0224] The inflow path 111 is formed by a first hole h1 in the cover 101, and the outflow path 112 is formed by a second hole h2 in the cover 101. As described above, by forming the inflow path 111 and the outflow path 112 with holes h1 and h2, the flow path lengths of the inflow path 111 and the outflow path 112 are shortened. Therefore, the inner diameters of the inflow path 111 and the outflow path 112 can be ensured to a certain extent, and their flow path resistance can be reduced. The processing of the inflow path 111 and the outflow path 112 is also easy.

[0225] The oxygen sensor 51 is configured to generate heat when switched on, and airflow is created inside the housing 101 as the oxygen sensor 51 heats up. Therefore, airflow can be ensured inside the housing 101, and the oxygen concentration can be detected with high accuracy using the oxygen sensor 51.

[0226] The sensor housing 90 includes an inlet 94 for introducing air into the interior of the sensor housing 90, and a cover 101 is disposed between the inlet 94 and the oxygen sensor 51. Therefore, it is possible to prevent corrosive components entering from the inlet 94 from contacting the oxygen sensor 51.

[0227] The inlet 94 is located below the oxygen sensor 51, and the cover 101 has a portion (body 102) located below the oxygen sensor 51. Therefore, it is possible to prevent corrosive components entering from the inlet 94 below the oxygen sensor 51 from contacting the oxygen sensor 51.

[0228] The inlet 94 includes a first inlet 94a for introducing air from inside the object space into the sensor housing 90, and a second inlet 94b for introducing air from outside the object space into the sensor housing 90. At least one of the first inlet 94a and the second inlet 94b is arranged below the oxygen sensor 51, and the cover 101 has a portion arranged below the oxygen sensor 51.

[0229] Therefore, it is possible to prevent corrosive components entering from the first inlet 94a or the second inlet 94b on the lower side of the oxygen sensor 51 from contacting the oxygen sensor 51.

[0230] In the first embodiment, at least a portion of the moisture in the air flowing from the branch pipe 81 into the sensor housing 90 is removed by the gas-liquid separator 85. This prevents the oxygen sensor 51 and carbon dioxide sensor 52 from malfunctioning due to moisture adhesion.

[0231] - Variations of the first embodiment -

[0232] (Variation Example 1)

[0233] In the first embodiment, both the first inlet 94a and the second inlet 94b are arranged below the oxygen sensor 51, but it is also possible to configure one of the first inlet 94a and the second inlet 94b to be located below the oxygen sensor 51.

[0234] If the first inlet 94a is positioned below the oxygen sensor 51, and a portion of the cover 101 is positioned between the first inlet 94a and the oxygen sensor 51, contact between the oxygen sensor 51 and corrosive components due to outside air during sensor calibration can be prevented. If the second inlet 94b is positioned below the oxygen sensor, and a portion of the cover 101 is positioned between the second inlet 94b and the oxygen sensor, contact between the oxygen sensor 51 and corrosive components due to inside air during normal operation can be prevented.

[0235] (Variation Example 2)

[0236] In the first embodiment, the cover unit 100 forms an inflow path 111 and an outflow path 112 by forming holes in the cover 101. However, the cover unit 100 may also form an inflow path 111 and an outflow path 112 by providing cylindrical portions 131 and 132 of the cover 101.

[0237] like Figure 16 As shown, in the modified example 2, a first cylindrical portion 131 and a second cylindrical portion 132 are connected around the body 102 of the cover 101 on the cover unit 100. An inflow passage 111 is formed inside the first cylindrical portion 131, connecting the outside of the cover 101 to the storage space 104. An outflow passage 112 is formed inside the second cylindrical portion 132, connecting the outside of the cover 101 to the storage space 104. In this example, the first cylindrical portion 131 and the second cylindrical portion 132 are opposite each other. The basic structure, otherwise, is the same as in the first embodiment.

[0238] Second Implementation Method

[0239] The second embodiment is an example of using an adsorption component 105 that adsorbs corrosive components in the air as a contact suppression part, based on the cover unit 100 of the first embodiment.

[0240] The adsorption component 105 is arranged inside the sensor housing 90. Figure 17 An example is shown in which the adsorption component 105 is disposed on the bottom surface of the sensor housing 90. The adsorption component 105 has a substrate and an adsorbent (e.g., zeolite or activated carbon) supported on the substrate.

[0241] The second embodiment is identical to the first embodiment in structure, except that the adsorption component 105 is used instead of the wall component 101. Therefore, descriptions of other structures besides the adsorption component 105 are omitted.

[0242] In this second embodiment, corrosive components contained in the air introduced into the sensor housing 90 are adsorbed by the adsorption component 105 within the sensor housing 90. Therefore, it is possible to prevent the oxygen sensor 51 from coming into contact with corrosive components.

[0243] It should be noted that the adsorption component 105 can also be disposed inside the sensor housing 90 together with the wall component 101 of the first embodiment. If the above configuration is adopted, the wall component 101 and the adsorption component 105 can be used to suppress the contact between the oxygen sensor 51 and corrosive components.

[0244] -Modifications of the Second Embodiment-

[0245] (Variation Example 1)

[0246] like Figure 18 As shown, the adsorption component 105 can also be disposed within the sensor housing 90. Figure 17 Different locations, such as the back of the housing cover 92 of the sensor housing 90, etc. Even with the above configuration, it is possible to suppress the contact between corrosive components in the air and the oxygen sensor 51 by using the adsorption component 105 to adsorb corrosive components in the air.

[0247] (Variation Example 2)

[0248] Adsorption component 105 can also be used with Figure 17 and Figure 18 Examples of different arrangements are set in air circuit 3.

[0249] like Figure 19 As shown, the adsorption component 105 is arranged on the back side (the side where the second inlet 94b is formed) of the sensor housing 90, on the same surface as the oxygen sensor 51 and the cover 101. The adsorption component 105 is formed by supporting the adsorbent on an approximately rectangular substrate.

[0250] In this structure, if the air entering through the second inlet 94b contains corrosive components, these components will be effectively adsorbed by the adsorption component 105. The air is then further introduced into the cover 101 through the inflow path 111. Therefore, contact between corrosive components and the oxygen sensor 51 can be effectively suppressed.

[0251] (Variation Example 3)

[0252] Figure 20 This is a partially enlarged view of the air circuit 3 involved in Modification 3. As shown, in this Modification 3, the adsorption component 105 is arranged at the connecting pipe 59, which is the first inlet path 59a for introducing air into the sensor housing 90. Figure 20 As shown by the imaginary outline, the adsorption component 105 can also be arranged together with, for example, the membrane filter 54 described above at the inlet 94, and the connecting tube 59 is connected to the sensor housing 90 through the inlet 94.

[0253] Alternatively, the number of adsorption components 105 provided in the air circuit 3 can be set to multiple, and the adsorption components 105 can be arranged inside the sensor housing 90 and in other locations. In addition, multiple adsorption components 105 can be arranged at both the connecting pipe 59 and the second inlet 94b. The connecting pipe 59 is the first inlet 59a for introducing external air into the sensor housing 90, and the second inlet 94b constitutes the second inlet 59b for introducing air from inside the chamber into the sensor housing 90.

[0254] According to this modified example 3, corrosive components in the air introduced into the sensor housing 90 are adsorbed by the adsorption component 105 near the sensor housing 90. As a result, contact between corrosive components and the oxygen sensor 51 can be suppressed, thereby suppressing the deterioration of the oxygen sensor 51.

[0255] (Variation Example 4)

[0256] The adsorption component 105 can also be located in other locations besides inside the sensor housing 90.

[0257] Figure 21 This is a diagram showing the air circuit 3 of the CA device according to a variation 4 of the second embodiment. In this variation 4, the adsorption member 105 is arranged together with the membrane filter 76 in the inlet section where external air flows into the air circuit 3.

[0258] In this modified example 4, one end of the bypass passage 78, which is connected in parallel with the first adsorption cylinder 34, is connected to the pressurization passage 42, and the other end of the bypass passage 78 is connected to the oxygen discharge passage 45. A bypass switch valve 78a is provided on the bypass passage 78. In this structure, 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. As described above, the second passage 76 can be any passage that branches off from the first passage and can introduce external air into the oxygen sensor 51, or it can be a passage that branches off from the first passage 75 and then rejoins it.

[0259] The other structures of this variation 4 are the same as those of variation 1.

[0260] According to this modified example 4, the adsorption component 105 can adsorb corrosive components contained in the external air flowing into the air circuit 3. Therefore, when performing the calibration operation of introducing external air into the oxygen sensor 51, it is possible to prevent corrosive components from contacting the oxygen sensor 51.

[0261] Third Implementation Method

[0262] like Figure 22 , Figure 23 As shown, the sensor housing 90 can also be placed outside the housing space instead of inside the housing. Figure 22 As shown in the piping system diagram, the sensor housing 90, located outside the enclosure, is connected to the membrane filter 54 located in the secondary space S22 inside the enclosure via the second inlet 59b. Even with the above configuration, it is possible to prevent corrosive components in the air from contacting the oxygen sensor 51.

[0263] In a structure where the sensor housing 90 is arranged in the external space of the enclosure, as shown in this example. Figures 9-11 The first inlet 94a shown introduces outside air into the sensor housing 90 during oxygen sensor 51 calibration, and the second inlet 94b introduces inside air into the sensor housing 90.

[0264] Other Implementation Methods

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

[0266] For example, in the above embodiment, oxygen sensor 51 was described as a gas sensor designed to suppress deterioration caused by corrosive components. However, deterioration can also occur in other gas sensors besides oxygen sensor 51. Therefore, the cover 101 and contact suppression part 105 of the above embodiment can also be provided for other gas sensors, such as the carbon dioxide sensor 52 described above, which may be used in the transport container 1 including an air composition regulating device, such as ethylene sensor or refrigerant leak sensor. The ethylene sensor is a sensor that detects the ethylene concentration inside the container, and the refrigerant leak sensor is a sensor that detects refrigerant leaking into the container. Oxygen sensor 51 and carbon dioxide sensor 52 can also be used in ways other than those described in the embodiment.

[0267] In the above embodiments, hydrogen sulfide is used as an example of a corrosive component, but the contact inhibition part 100 of each embodiment can also be provided for other corrosive components, including calcium, chlorine, phosphorus, etc.

[0268] In the above embodiment, an example was described in which the gas sensor, namely the oxygen sensor 51, was arranged inside the sensor housing 90. However, the contact suppression part 100 may also be provided without the sensor housing 90.

[0269] 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.

[0270] The conveying section of the above-described embodiment can also be constructed using an air supply mechanism.

[0271] In the above embodiments, one adsorption cylinder is used for nitrogen adsorption and desorption, respectively, as the first adsorption section and the second adsorption section. 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, for a total of six adsorption cylinders.

[0272] 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 employ the following structure: using gas separation membranes with different nitrogen permeability and oxygen (and carbon dioxide) permeability to generate nitrogen-rich air and oxygen-rich air, and using the nitrogen-rich air and oxygen-rich air to adjust the composition of the air in the chamber.

[0273] 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 to this. 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 cold storage, or an ambient temperature storage. The refrigeration device may also be a device for cooling the internal space of a fixed storage warehouse (cold storage), rather than a device for cooling the internal space of a transport storage warehouse.

[0274] The cover unit 100 may also consist of only the cover 101.

[0275] The embodiments and modifications have been described above; however, it is understood that various changes can be made to the methods and specific circumstances without departing from the spirit and scope of the claims. As long as the function of the object of this disclosure is not affected, the above embodiments and modifications can be appropriately combined and substituted.

[0276] -Industry Applicability-

[0277] In summary, this disclosure is useful for air composition conditioning devices, refrigeration devices for transportation, and containers for transportation.

[0278] - Symbol Explanation -

[0279] 1. Transport containers

[0280] 2. Container body

[0281] 3. Air circuit

[0282] 10. Refrigeration equipment for transportation (refrigeration unit)

[0283] 20 Refrigerant Circuit

[0284] 21. Compressor (Components)

[0285] 22. Condenser (Components)

[0286] 23. Expansion Valve (Components)

[0287] 24. Evaporator (Components)

[0288] 31 Air Pump (Transportation Section)

[0289] 34 First Adsorption Cylinder (Adjustment Section)

[0290] 35 Second Adsorption Cylinder (Adjustment Section)

[0291] 51 Oxygen Sensor (Gas Sensor)

[0292] 51a Testing Department

[0293] 59 Second connecting pipe (inlet path)

[0294] 60. Air composition conditioning device (air composition conditioning unit)

[0295] 90 sensor housing

[0296] 94. Inlet / Outlet (Inlet Road)

[0297] 94a First Inlet

[0298] 94b Second Inlet

[0299] 100-unit

[0300] 101 masks

[0301] 105 Adsorption Components

[0302] 111 Inflow Route

[0303] 112 outflow path

[0304] 131 First tube section

[0305] 132 Second tube section

[0306] h1 First hole

[0307] h2 second hole

Claims

1. An air composition regulating device, characterized in that: The air composition regulating device includes a conveying unit (31), a regulating unit (34, 35), an air circuit (3), a gas sensor (51), a sensor housing (90), and a cover unit (100). The conveying unit (31) conveys air. The regulating units (34, 35) regulate the composition of the air in the target space. In the air circuit (3), air is introduced into the regulating unit (34, 35) by the conveying unit (31), and the air, whose composition has been regulated, is supplied to the target space. The gas sensor (51) is arranged in the object space and measures the composition of the air. The sensor housing (90) houses the gas sensor (51) and includes an inlet (94) for introducing air into the interior of the sensor housing (90). The cover unit (100) is disposed inside the sensor housing (90) and includes a cover (101) covering the gas sensor (51), an inflow path (111) for introducing air into the cover (101), and an outflow path (112) for allowing air to flow out of the cover (101). The inflow path (111) connects the space between the sensor housing (90) and the cover (101) with the interior of the cover (101). The outflow path (112) connects the space between the sensor housing (90) and the cover (101) with the interior of the cover (101).

2. The air composition regulating device according to claim 1, characterized in that: The inner diameter of the inflow path (111) and the inner diameter of the outflow path (112) are 1 mm or more and 4 mm or less.

3. The air composition regulating device according to claim 1, characterized in that: The outflow path (112) is located on the upper part of the cover (101).

4. The air composition regulating device according to claim 1, characterized in that: The inflow path (111) is located at the lower part of the cover (101).

5. The air composition regulating device according to claim 1, characterized in that: The detection section (51a) of the gas sensor (51) is located on a straight line connecting the inflow path (111) and the outflow path (112).

6. The air composition regulating device according to claim 1, characterized in that: The inflow path (111) is formed by a first hole (h1) in the cover (101). The outflow path (112) is formed by a second hole (h2) in the cover (101).

7. The air composition regulating device according to claim 1, characterized in that: The inflow path (111) is formed by a first cylindrical portion (131) connected to the cover (101). The outflow path (112) is formed by a second cylindrical section (132) connected to the cover (101).

8. The air composition regulating device according to claim 1, characterized in that: The gas sensor (51) is configured to generate heat when it is switched on. The cover (101) is configured to generate an airflow as the gas sensor (51) heats up.

9. The air composition regulating device according to claim 1, characterized in that: The inlet (94) is located below the gas sensor (51). The cover (101) has a portion arranged below the gas sensor (51).

10. The air composition regulating device according to claim 1, characterized in that: The inlet (94) includes a first inlet (94a) and a second inlet (94b). The first inlet (94a) introduces air from inside the object space into the sensor housing (90), and the second inlet (94b) introduces air from outside the object space into the sensor housing (90). At least one of the first inlet (94a) and the second inlet (94b) is arranged below the gas sensor (51). The cover (101) has a portion arranged below the gas sensor (51).

11. The air composition regulating device according to any one of claims 1 to 8, characterized in that: The air composition regulating device includes a contact suppression part that prevents corrosive components in the air from contacting the gas sensor (51). The contact inhibition part has an adsorption component (105) that adsorbs corrosive components in the air.

12. The air composition regulating device according to claim 11, characterized in that: The air composition regulating device includes a sensor housing (90) that houses the gas sensor (51) inside. The adsorption component (105) is arranged inside the sensor housing (90).

13. The air composition regulating device according to claim 11, characterized in that: The air composition regulating device includes a sensor housing (90) that houses the gas sensor (51) inside. An air inlet (59) for introducing air into the interior of the sensor housing (90) is connected to the sensor housing (90). The adsorption component (105) is arranged in the inlet path (59).

14. The air composition regulating device according to claim 11, characterized in that: The air composition regulating device includes a sensor housing (90) that houses the gas sensor (51) inside. The sensor housing (90) has an inlet (94) for introducing air into the interior of the sensor housing (90). The adsorption component (105) is arranged at the inlet (94).

15. The air composition regulating device according to claim 11, characterized in that: The adsorption component (105) is arranged in the inlet section where air flows into the air circuit (3).

16. The air composition regulating device according to claim 11, characterized in that: The adsorption component (105) adsorbs corrosive components containing sulfur or phosphorus.

17. A refrigeration apparatus 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 a target space, wherein the air in the target space is cooled by an evaporator (24) in the refrigerant circuit (20), 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 16.

18. A transport container, the transport container comprising a container body (2) for transporting fresh goods, and a transport refrigeration device (10) for cooling the interior of the container body (2) as the target space, characterized in that: The transport refrigeration device (10) is composed of the refrigeration device according to claim 17.

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