Indoor freezer and refrigeration storage

Abstract

To provide an indoor freezer capable of suppressing wrong detection of refrigerant gas leaking indoors.SOLUTION: An indoor freezer for cooling an indoor space (S) comprises: a refrigerant circuit (R) that performs a refrigeration cycle; a refrigerant sensor (50) that detects refrigerant leaked in the indoor space (S); a first sensor (51) that detects an indicator different from the refrigerant; and a control unit (100) that determines leakage of the refrigerant in the indoor space (S) based on the detection results of the refrigerant sensor (50) and first sensor (51).SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to an in - store refrigeration device and a refrigerated storage.

Background Art

[0002] The in - store refrigeration device disclosed in Patent Document 1 includes a refrigerant sensor provided in the in - store space of a container. The refrigerant sensor detects refrigerant gas leaked from the refrigerant circuit into the container in - store space.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a refrigerated storage such as the container of Patent Document 1, when miscellaneous gas is generated in the in - store space, there is a risk that the refrigerant sensor may misdetect the miscellaneous gas as refrigerant gas.

[0005] An object of the present disclosure is to provide an in - store refrigeration device that suppresses misdetection of refrigerant leaking into the in - store space.

Means for Solving the Problems

[0006] The first aspect is an in - store refrigeration device that cools an in - store space (S) using a refrigerant circuit (R) that performs a refrigeration cycle, a refrigerant sensor (50) for detecting refrigerant leaked in the in - store space (S), a first sensor (51) for detecting an index different from the refrigerant, and a control unit (100) that determines leakage of refrigerant in the in - store space (S) based on the detection results of the refrigerant sensor (50) and the first sensor (51).

[0007] With only the refrigerant sensor (50), there is a risk of misdetecting, for example, miscellaneous gases and refrigerant gas generated in the storage space (S). In contrast, in the first aspect, in addition to the detection result of the refrigerant sensor (50), the detection result of the first sensor (51) is used for determining refrigerant leakage. By determining that the change in the storage environment detected by the first sensor (51) is due to the refrigerant gas, false detection of refrigerant leakage in the storage space (S) can be suppressed.

[0008] The second aspect is as follows in the first aspect. The first sensor (51) detects the gas components in the storage space (S). When the control unit (100) detects refrigerant leakage by the refrigerant sensor (50) and detects that the concentration of the gas components in the storage space (S) or the degree of change in the concentration is outside a predetermined range by the first sensor (51), it determines the refrigerant leakage in the storage space (S).

[0009] In the second aspect, in addition to detecting the gas components in the storage space (S), the first sensor (51) can also be used for determining refrigerant leakage.

[0010] The third aspect is as follows in the second aspect. The first sensor (51) detects the humidity, oxygen, or carbon dioxide in the storage space (S).

[0011] In the third aspect, sensors of the type used for detecting humidity, oxygen, or carbon dioxide are less likely to be misdetected with miscellaneous gases such as ethylene gas. By using such sensors and the refrigerant sensor (50) for determining refrigerant leakage, the reliability of the refrigerant leakage determination can be improved. Also, such sensors are already installed in the storage space (S), and there is no need to newly install sensors.

[0012] The fourth aspect is as follows in the first aspect. The first sensor (51) detects the pressure of the gas in the storage space (S). When the control unit (100) detects refrigerant leakage by the refrigerant sensor (50) and detects that the pressure of the gas in the storage space (S) or the degree of change in the pressure is outside a predetermined range by the first sensor (51), it determines refrigerant leakage in the storage space (S).

[0013] In the fourth aspect, when refrigerant leaks, the pressure of the gas in the storage space (S) increases. By using this change in the pressure of the gas in the storage space (S) for determining refrigerant leakage, it can be achieved.

[0014] The fifth aspect is, in the first aspect, further including an indoor fan (30) for circulating the air in the storage space (S), the first sensor (51) detects the current value of a motor (30a) that drives the indoor fan (30), when the control unit (100) detects refrigerant leakage by the first sensor (51) and detects that the current value of the motor (30a) or the degree of change in the current value is outside a predetermined range by the first sensor (51), it determines refrigerant leakage in the storage space (S).

[0015] In the fifth aspect, when refrigerant leaks into the storage space (S), the density of the gas composition in the storage space (S) increases. Therefore, the operating load of the indoor fan (30) increases and the current value flowing through the motor (30a) rises. This change in the current value can be used for determining refrigerant leakage.

[0016] The sixth aspect is, in the first aspect, the first sensor (51) detects the pressure or temperature of the refrigerant flowing through the refrigerant circuit (R), when the control unit (100) detects refrigerant leakage by the first sensor (51) and detects that an index indicating the pressure or temperature of the refrigerant flowing through the refrigerant circuit (R) or the degree of change in the index is outside a predetermined range by the first sensor (51), it determines refrigerant leakage in the storage space (S).

[0017] In the sixth aspect, when the refrigerant leaks from the refrigerant circuit (R), the pressure and temperature of the refrigerant in the refrigerant circuit (R) change. The change in the refrigerant pressure or refrigerant temperature of this refrigerant circuit (R) can be used to determine refrigerant leakage.

[0018] The seventh aspect is a refrigerated storage equipped with an in - storage refrigeration device according to any one of the first to sixth aspects.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0020] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or its uses. Also, the components of each of the following embodiments, modification examples, and other examples can be combined or partially replaced within the scope where the present invention can be implemented.

[0021] (1) Overall Configuration of the Container As shown in Fig. 1, the in - container refrigeration device (10) is applied to the container (1). The container (1) is an example of a refrigerated storage. The container (1) is used for maritime transportation. The container (1) is a refrigerated container that cools the air inside it.

[0022] The overall configuration of the container (1) in this embodiment will be described with reference to Figs. 1 to 3. In the following description, the terms related to "front", "rear", "left", "right", "upper", and "lower" are based on the directions indicated by the arrows in Fig. 1.

[0023] The container (1) has a container body (2) and an in - container refrigeration device (10). The in - container space (S) of the container body (2) is partitioned into a storage space (3) and an air passage (19). The storage space (3) and the air passage (19) communicate with each other so that air circulates between them. Storage items such as food and plants are stored in the storage space (3). The in - container refrigeration device (10) cools the air in the storage space (3). A front opening (4) is formed on the front surface of the container body (2). The in - container refrigeration device (10) is attached to the container body (2) so as to close the front opening (4) of the container body (2).

[0024] (2) In - container refrigeration device The in - container refrigeration device (10) has a casing (11). The casing (11) forms a lid for the front opening (4) of the container body (2). The casing (11) has a casing body (12) and a partition plate (13). The casing body (12) partitions the outside space (5) outside the container body (2), which is the out - of - container space, from the storage space (3). The partition plate (13) is located on the back side (rear side) of the casing (11).

[0025] The in - container refrigeration device (10) includes a refrigerant circuit (R) that performs a refrigeration cycle. As equipment arranged outside the container, the in - container refrigeration device (10) has a compressor (25), an outdoor heat exchanger (26), and an outdoor fan (27). As equipment arranged inside the container, the in - container refrigeration device (10) has an indoor heat exchanger (29) and an indoor fan (30).

[0026] (2-1) Casing body As shown in Fig. 2, the casing body (12) has a flat plate portion (12a) and a recessed portion (12b). The flat plate portion (12a) is formed at the upper part of the casing body (12) so as to be substantially flush with the front opening (4) of the casing (11). As shown in Fig. 1, an inspection window (22) and a ventilation device (40) are provided on the flat plate portion (12a). The inspection window (22) is arranged at a portion on the right side of the flat plate portion (12a). The ventilation device (40) is arranged at a portion on the left side of the flat plate portion (12a). The inspection window (22) is a transparent window for checking the inside of the casing body (12). The ventilation device (40) ventilates the accommodation space (3).

[0027] The recessed portion (12b) is formed at the lower part of the casing (11). The recessed portion (12b) is recessed rearward from the lower end of the flat plate portion (12a). An external storage space (14) is formed on the front side of the recessed portion (12b). An internal storage space (15) is formed between the flat plate portion (12a) and the partition plate (13) above the recessed portion (12b). The lower end of the recessed portion (12b) constitutes a bottom plate (12c). The bottom plate (12c) extends across both left and right ends of the casing body (12).

[0028] The casing body (12) is configured by laminating an external casing (16), a heat insulating layer (17), and an internal casing (18) in the thickness direction (front-rear direction). The external casing (16) faces the external space (5). The internal casing (18) faces the inside of the storage. Thus, the recessed portion (12b) has side walls (16a) of the external casing (16) extending in the vertical direction and side walls of the internal casing (18). The side walls (16a) of the external casing (16) extending in the vertical direction separate the external space (5) and the air passage (19). The heat insulating layer (17) is provided between the external casing (16) and the internal casing (18). The external casing (16) is made of an aluminum material. The internal casing (18) is made of a reinforced fiber plastic (FRP). The heat insulating layer (17) is made of a foamed resin.

[0029] (2-2) Partition Plate and Air Passage As shown in Fig. 2, the partition plate (13) is a plate-like member located on the rear side of the recess (12b). The partition plate (13) extends vertically so as to be at a predetermined interval from the rear surface of the recess (12b). An air passage (19) through which the air inside the cabinet flows is formed between the casing body (12) and the partition plate (13). An inlet (20) is formed between the upper end of the partition plate (13) and the upper wall (2a) of the container body (2). The inlet (20) communicates the storage space (3) with the inflow end of the air passage (19). An outlet (21) is formed between the lower end of the partition plate (13) and the lower wall (2b) of the container body (2). The outlet (21) communicates the storage space (3) with the outflow end of the air passage (19). In the air passage (19), air flows in the vertical direction. Specifically, in the air passage (19), air flows in the vertical direction.

[0030] (2-3) Component Parts in the Space outside the Cabinet In the storage space (14) outside the cabinet, a compressor (25), an outdoor heat exchanger (26), and an outdoor fan (27) are provided. The compressor (25) is installed on the bottom plate (12c) of the casing (11). The compressor (25) is arranged near the lower part of the storage space (14) outside the cabinet. The compressor (25) is arranged on the right side of the storage space (14) outside the cabinet.

[0031] The outdoor fan (27) is located near the upper part in the storage space (14) outside the cabinet. The outdoor fan (27) is driven by an outdoor fan motor (27a). The outdoor fan (27) is a propeller fan. As shown in Fig. 2, an external passage (28) through which the outdoor air flows is formed on the back side of the outdoor fan (27).

[0032] The outdoor heat exchanger (26) is provided at a height position between the outdoor fan (27) and the compressor (25) in the storage space (14) outside the cabinet. The outdoor heat exchanger (26) is located in the external passage (28). The outdoor heat exchanger (26) is a fin-and-tube type heat exchanger.

[0033] (2-4) Component Parts in the Space inside the Cabinet An air passage (19) is provided with an indoor heat exchanger (29) and an indoor fan (30). The indoor heat exchanger (29) and the indoor fan (30) are provided in an indoor accommodation space (15) which is a part of the air passage (19). The indoor heat exchanger (29) is supported by a casing (11) so as to span a casing main body (12) and a partition plate (13). The indoor heat exchanger (29) is a fin-and-tube type heat exchanger.

[0034] The indoor fan (30) circulates the air in the indoor space (S). By the indoor fan (30), the air in the indoor space (S) circulates between the accommodation space (3) and the air passage (19). The indoor fan (30) is driven by an indoor fan motor (30a). The indoor fan (30) is a propeller fan.

[0035] (2-5) Refrigerant circuit As shown in FIG. 3, the indoor refrigeration device (10) has a refrigerant circuit (R). The refrigerant circuit (R) is filled with a refrigerant. The refrigerant circuit (R) performs a vapor compression refrigeration cycle by circulating the refrigerant.

[0036] For the refrigerant of this embodiment, 2,3,3,3 tetrafluoropropene (hereinafter sometimes referred to as R1234yf refrigerant or R1234yf) is used. The refrigerant may be difluoromethane (R32), 1,3,3,3 tetrafluoropropene (R1234ze). The refrigerant may be a single refrigerant or a mixed refrigerant in which other refrigerants are mixed. The mixed refrigerant may be a refrigerant composed of two kinds, 2,3,3,3 tetrafluoropropene (R1234yf) and difluoromethane (R32). The mixed refrigerant may be a refrigerant (R454C) composed of two kinds, 78.5% by weight of 2,3,3,3 tetrafluoropropene (R1234yf) and 21.5% by weight of difluoromethane (R32). The refrigerant may be a flammable refrigerant. The flammable refrigerant may be propane (R290), methane (R50), ethane (R170), butane (R600), isobutane (R600a) which are strongly flammable natural refrigerants. Also, the refrigerant may be carbon dioxide (CO2) which is a natural refrigerant.

[0037] The refrigerant circuit (R) mainly includes a compressor (25), an outdoor heat exchanger (26), an expansion valve (31), and an indoor heat exchanger (29).

[0038] The compressor (25) compresses the inhaled refrigerant and discharges the compressed refrigerant. A discharge pipe (32) is connected to the discharge part of the compressor (25), and a suction pipe (33) is connected to the suction part of the compressor (25). An accumulator (34) is provided in the suction pipe (33). The accumulator (34) is a container for storing liquid refrigerant.

[0039] The outdoor heat exchanger (26) exchanges heat between the refrigerant flowing inside it and the outdoor air. The gas end of the outdoor heat exchanger (26) communicates with the discharge pipe (32), and the liquid end of the outdoor heat exchanger (26) is connected to the liquid end of the indoor heat exchanger (29) via a liquid pipe (35). The outdoor heat exchanger (26) functions as a radiator (condenser) for the refrigerant to release heat to the air.

[0040] The expansion valve (31) is provided in the liquid pipe (35). The expansion valve (31) reduces the pressure of the high-pressure refrigerant to a low-pressure refrigerant and is an electronic expansion valve with an adjustable opening degree. A receiver (36) is provided between the outdoor heat exchanger (26) and the expansion valve (31) in the liquid pipe (35). The receiver (36) is a container for storing the surplus refrigerant in the refrigerant circuit (R).

[0041] The indoor heat exchanger (29) exchanges heat between the refrigerant flowing inside it and the indoor air. The gas end of the indoor heat exchanger (29) communicates with the suction pipe (33). The indoor heat exchanger (29) functions as an evaporator for the refrigerant to absorb heat from the air.

[0042] The refrigerant circuit (R) has a bypass pipe (37). The inflow end of the bypass pipe (37) communicates with the discharge pipe (32), and the outflow end of the bypass pipe (37) communicates with the liquid pipe (35). The bypass pipe (37) sends the refrigerant discharged from the compressor (25) to the indoor heat exchanger (29) by bypassing the outdoor heat exchanger (26).

[0043] A first valve (38) and a second valve (39) are provided in the refrigerant circuit (R). The first valve (38) is provided between the discharge side of the compressor (25) and the gas end of the outdoor heat exchanger (26), and on the downstream side of the connection portion of the bypass pipe (37). The second valve (39) is provided in the bypass pipe (37). The first valve (38) and the second valve (39) are constituted by electromagnetic on-off valves. The first valve (38) and the second valve (39) may be flow control valves with adjustable opening degrees.

[0044] (2-6) Operating operation The in-ware refrigeration device (10) performs a cooling operation and a defrosting operation.

[0045] During the cooling operation, a refrigeration cycle is performed in which the refrigerant compressed by the compressor (25) condenses in the outdoor heat exchanger (26), is decompressed by the expansion valve (31), and evaporates in the in-ware heat exchanger (29). The air flowing out from the accommodation space (3) into the air passage (19) is cooled by the in-ware heat exchanger (29) that functions as an evaporator. The cooled air is sent to the accommodation space (3) (refer to the arrow in FIG. 2).

[0046] During the defrosting operation, the refrigerant compressed by the compressor (25) flows through the bypass pipe (37) and then through the in-ware heat exchanger (29). The frost on the surface of the in-ware heat exchanger (29) melts due to the heat of the refrigerant flowing through the inside of the in-ware heat exchanger (29).

[0047] (3) Control unit As shown in FIG. 4, the in-ware refrigeration device (10) includes a control unit (100). The control unit (100) controls the in-ware refrigeration device (10). The control unit (100) includes a microprocessor, an electric circuit, and an electronic circuit. The microprocessor includes a CPU (Central Processing Unit), a memory, a communication interface, analog input / output, and a contact input / output interface. Various programs for the CPU to execute and data used by the programs are stored in the memory.

[0048] The control unit (100) controls the mechanical elements of the in - store refrigeration device (10). As shown in FIG. 4, this target value may be a value that can be arbitrarily set by the user of the in - store refrigeration device (10) via the operation unit (101). The operation unit (101) is composed of, for example, a touch panel, a remote controller, and a DIP switch provided in the in - store refrigeration device (10). The operation unit (101) may be a communication terminal connected to the in - store refrigeration device (10) via a network. The target value does not necessarily have to be set by the user, and may be a value automatically determined by the control unit (100) according to, for example, the operation mode and operation conditions.

[0049] (4) Refrigerant sensor As shown in FIGS. 2 and 4, the in - store refrigeration device (10) is provided with a refrigerant sensor (50). The refrigerant sensor (50) detects the refrigerant leaked from the refrigerant circuit (R) inside the container (1). Specifically, the refrigerant sensor (50) detects using the refrigerant contained in the air flowing through the air passage (19) as an indicator. The refrigerant sensor (50) is arranged below the in - store fan (30). Hereinafter, the air containing the leaked refrigerant and the air not containing the leaked refrigerant may be collectively referred to as air. The details of the refrigerant sensor (50) will be described later.

[0050] (5) Notification device As shown in FIG. 4, the in - store refrigeration device (10) is provided with a notification unit (60). The notification unit (60) notifies the user of predetermined information. The notification unit (60) includes a predetermined speaker or display. For example, when the control unit (100) determines that there is an abnormality in the in - store refrigeration device (10) or the in - store space (S), the notification unit (60) announces the abnormality from the speaker or displays it on the display.

[0051] (6) Problem of false detection of the refrigerant sensor If the refrigerant (refrigerant gas) leaks into the indoor space (S) and the properties of the refrigerant contained in the air flowing into the indoor space (S) are similar to those of the miscellaneous gas generated in the indoor space (S), the refrigerant sensor (50) may detect the miscellaneous gas as the refrigerant gas. For example, a sensor using the NDIR (Non Dispersive InfraRed) method detects a specific gas by utilizing the fact that various gases absorb specific wavelengths in the infrared region. In this NDIR type refrigerant sensor, when the absorption wavelength region of the refrigerant gas and the absorption wavelength region of the miscellaneous gas overlap, or when the absorption wavelength regions are relatively close to each other, the refrigerant sensor cannot distinguish between the refrigerant gas and the miscellaneous gas and may detect the miscellaneous gas as the refrigerant gas.

[0052] Specifically, assume that R1234yf or R32 is used as the refrigerant of the indoor refrigeration device, and fruits that generate ethylene gas are stored in the indoor space. The peak of the absorption wavelength of the refrigerant is around 3.3 μm, and ethylene gas also has a peak of the absorption wavelength in the vicinity. Therefore, in this combination of gases, the NDIR type refrigerant sensor may not be able to distinguish and detect the ethylene gas generated from the fruits and the refrigerant gas leaked into the indoor space.

[0053] On the other hand, the indoor refrigeration device (10) of the present embodiment includes a first sensor (51) that detects an index different from the refrigerant. In other words, the first sensor (51) does not detect the refrigerant leaking into the indoor space (S), which is the index detected by the refrigerant sensor (50). The indoor refrigeration device (10) of the present embodiment determines the leakage of the refrigerant in the indoor space (S) based on the detection result of the refrigerant sensor (50) and the detection result of the first sensor (51). The first sensor (51) will be specifically described below.

[0054] The index different from the refrigerant in the present embodiment is a gas component in the indoor space (S) other than the refrigerant. The first sensor (51) of the present embodiment detects water vapor, which is a gas component in the indoor space (S). The first sensor (51) is a humidity sensor (51) that detects the humidity in the indoor space (S). The humidity may be either relative humidity or absolute humidity.

[0055] The humidity sensor (51) is disposed in the interior space (S). The humidity sensor (51) is disposed above the interior fan (30). The humidity sensor (51) is disposed on the air suction side of the interior fan (30).

[0056] Here, the humidity sensor (51) of the present embodiment is of the NDIR type. Since the peak of the absorption wavelength of water molecules is around 2.7 μm, the absorption wavelength region in the infrared region of water molecules is different from the absorption wavelength region in the infrared region of the refrigerant (for example, R1234yf or R32). Therefore, with the NDIR type humidity sensor (51), false detection of the mixed gas and water molecules can be suppressed.

[0057] For example, when the humidity sensor (51) detects a behavior different from the normally assumed change in humidity, such as a rapid decrease in the humidity of the interior space, it can be presumed that this is due to the refrigerant leaking into the interior space (S) rather than due to humidity. In this way, the interior refrigeration device (10) of the present embodiment suppresses false detection of the refrigerant by the refrigerant sensor (50) by using the humidity sensor (51) having the property of being less likely to falsely detect other mixed gases.

[0058] (7) Operation of the control unit Hereinafter, the operation of detecting the refrigerant gas by the control unit (100) will be described with reference to FIG. 5. The control unit (100) determines whether there is a refrigerant leak in the interior space (S) based on the detection results of the refrigerant sensor (50) and the humidity sensor (51). Note that R1234yf is used as the refrigerant.

[0059] In step S11, the control unit (100) determines whether the refrigerant sensor (50) has detected the refrigerant gas. Specifically, the control unit (100) determines whether it has received a signal indicating that the refrigerant gas has been detected output from the refrigerant sensor (50). If it is determined that the refrigerant sensor (50) has detected the refrigerant gas (YES in step S11), step S12 is executed. If it is determined that the refrigerant sensor (50) has not detected the refrigerant gas (NO in step S11), step S11 is executed again.

[0060] In step S12, the control unit (100) determines whether the humidity sensor (51) detects that the degree of change in humidity is outside a predetermined range. Here, the degree of change in humidity indicates the degree of humidity decrease ΔRH in the internal space (S) over a certain period ΔT. For example, assuming the certain period ΔT is one minute, and the range within which the humidity is normally expected to change (decrease) when no refrigerant leaks into the internal space (S) during this one minute is defined as the predetermined range ΔRH0. If the humidity sensor (51) detects that the humidity decrease (ΔRH) in the internal space (S) over one minute exceeds the predetermined range ΔRH0, it can be inferred that the refrigerant gas has leaked into the internal space (S). For example, ΔRH indicates the difference between the relative humidity RH1 a certain period ago (e.g., one minute ago) and the current relative humidity RH2 (RH2 < RH1).

[0061] The degree of change in the humidity of the internal space (S) may be obtained by a predetermined calculation. For example, the degree of change in humidity can be obtained using the law of Boyle - Charles. Assuming the air temperature in the internal space (S) is 25°C and the relative humidity is 50%, the volume V R (m 3 ) corresponding to the refrigerant leakage amount (kg), the volume V (m 3 ) of the storage space (3), the saturated water vapor amount RH s (g / m 3 ) in the storage space (3) with an air temperature of 25°C, and the water vapor amount RH 25 (g / m 3 ) in the storage space (3) with an air temperature of 25°C. At this time, for the humidity RH when the refrigerant leaks into the internal space (S), RH = RH 25 / RH S ×V / (V + V R )…(Equation 1) holds. Based on Equation 1, ΔRH over a certain period ΔT can be obtained.

[0062] The certain period ΔT is set arbitrarily. The certain period ΔT may be set based on the stored items in the internal space (S), or may be set based on the region where the container is installed, the season, or the transportation route of the container. Based on the premise that the normally expected humidity change is relatively gentle, the shorter the certain period ΔT, the easier it is to distinguish between the change due to humidity and the change due to the leaked refrigerant.

[0063] When it is determined that the degree of change ΔRH of the humidity in the storage space (S) exceeds a predetermined range ΔRH0 (YES in step S12), step S13 is executed. When it is not determined that the degree of change ΔRH of the humidity in the storage space (S) exceeds the predetermined range ΔRH0 (NO in step S12), it is considered that no refrigerant gas has leaked into the storage space (S), and step S11 is executed again.

[0064] In step S13, the control unit (100) determines that the refrigerant has leaked into the storage space (S). The control unit (100) outputs to the notification unit (60) that the refrigerant gas has leaked into the storage space (S).

[0065] In step S14, the control unit (100) notifies the user from the notification unit (60) that the refrigerant gas has leaked by means of an alarm or display.

[0066] Also, in the present embodiment, the amount of refrigerant leaking into the storage space (S) can be estimated based on the degree of change in the humidity of the storage space (S). As shown in FIG. 6, assuming that the refrigerant filling amount of the in-room refrigeration device (10) is about 6 kg, when the leakage amount is 1 kg (the leakage amount is 17% of the refrigerant filling amount), when the leakage amount is 3 kg (the leakage amount is 51% of the refrigerant filling amount), and when the leakage amount is 6 kg (the leakage amount is 100% of the refrigerant filling amount), let the relative humidities of the storage space (S) be X1%, Y1%, and Z1% respectively (50% > X1 > Y2 > Z1). When the change in the humidity of the storage space (S) over a certain period changes from 50% to X1%, it can be inferred that 1 kg of refrigerant has leaked into the storage space (S). When the change in the humidity of the storage space (S) over a certain period changes from 50% to Y1%, it can be inferred that 3 kg of refrigerant has leaked into the storage space (S). When the change in the humidity of the storage space (S) over a certain period changes from 50% to Z1%, it can be inferred that 6 kg of refrigerant has leaked into the storage space (S).

[0067] (8) Features (8-1) Feature 1 The in-container refrigeration device (10) of the present embodiment includes a refrigerant sensor (50) for detecting refrigerant leaked in the in-container space (S) of the container (1), a first sensor (51) for detecting an index different from the refrigerant, and a control unit (100) for determining refrigerant leakage in the in-container space (S) based on the detection results of the refrigerant sensor (50) and the first sensor (51).

[0068] Since the refrigerant sensor (50) may detect miscellaneous gases that may be generated in the in-container space (S) such as ethylene gas, in the present embodiment, in addition to the detection result of the refrigerant sensor (50), the detection result of the first sensor (51) is used for determining refrigerant leakage. Thereby, when the refrigerant is detected by the refrigerant sensor (50) and the environmental change in the in-container space (S) detected by the first sensor (51) is due to refrigerant leakage, it can be determined that the refrigerant has leaked into the in-container space (S). In this way, false detection of refrigerant leakage can be suppressed and the detection accuracy of refrigerant leakage can be improved.

[0069] (8-2) Feature 2 When the control unit (100) of the in-container refrigeration device (10) of the present embodiment detects refrigerant leakage by the refrigerant sensor (50) and detects that the degree of change in the concentration of the gas component in the in-container space (S) by the first sensor (51) is outside a predetermined range, it determines refrigerant leakage in the in-container space (S). Thereby, the first sensor (51) can be used not only for the gas component in the in-container space (S) but also for determining refrigerant leakage.

[0070] (8-3) Feature 3 The first sensor (51) of the in-warehouse refrigeration device (10) of this embodiment is a humidity sensor that detects the humidity in the in-warehouse space (S). The humidity sensor (51) detects water vapor (water molecules) and is less likely to detect other miscellaneous gases. By using the humidity sensor (51) in the determination of refrigerant leakage in this way, the accuracy of the determination of refrigerant leakage can be improved. Further, the humidity sensor (51) is used for maintaining the freshness (humidity management) of the stored items stored in the storage space (3) of the container (1). By also using the humidity sensor (51) in the determination of refrigerant leakage in this way, it is not necessary to newly provide a sensor only for the determination of refrigerant leakage, and the number of parts can be reduced.

[0071] (9) Modification Hereinafter, a modification of the above embodiment will be described. Hereinafter, a configuration different from the above embodiment will be described.

[0072] (9-1) Modification 1 An index different from the refrigerant of Modification 1 is the pressure of the gas in the in-warehouse space (S). That is, the first sensor (51) of Modification 1 is a pressure sensor that detects the pressure of the gas in the in-warehouse space (S). When refrigerant gas leaks into the in-warehouse space (S), the pressure of the gas in the in-warehouse space (S) increases by the amount of the leaked refrigerant gas. Utilizing this, the control unit (100) of Modification 1 determines the leakage of the refrigerant in the in-warehouse space (S) based on the detection results of the refrigerant sensor (50) and the pressure sensor.

[0073] Specifically, when the control unit (100) of Modification 1 detects refrigerant leakage by the refrigerant sensor (50) and detects that the degree of change in the pressure of the gas in the in-warehouse space (S) by the pressure sensor is outside a predetermined range, it determines the leakage of the refrigerant in the in-warehouse space (S). Hereinafter, the air pressure in the in-warehouse space (S) may be referred to as the in-warehouse pressure.

[0074] The degree of change in the internal pressure indicates the degree of increase in the pressure of the gas in the internal space (S) over a certain period ΔT. For example, assuming the certain period ΔT is 1 minute, and the range within which the internal pressure is normally expected to decrease when no refrigerant leaks into the internal space (S) within this 1 minute is defined as a predetermined range ΔP0. When the pressure sensor detects that the degree of increase in the internal pressure ΔP of the internal space (S) within 1 minute exceeds the predetermined range ΔP0, it is presumed that the refrigerant gas has leaked into the internal space (S). For example, ΔP represents the difference between the internal pressure P1 a certain period (e.g., 1 minute) before the present and the current internal pressure P2 (P2 > P1).

[0075] The degree of change in the internal pressure may be obtained by a predetermined calculation. For example, the degree of change in the internal pressure can be obtained using Boyle's law and Charles's law. Specifically, for the internal pressure P1 due to refrigerant leakage, the volume V1 of the internal space, the standard atmospheric pressure P2 (1 atm), and the volume V of the refrigerant leakage amount R we have P1 = (V1 + V R ) × P2 / V1... (Equation 2).

[0076] By substituting known values into V1 and P2 in Equation 2, the internal pressure P1 after refrigerant leakage can be obtained based on the volume V R of the refrigerant leakage amount. Thus, in Variant 1, the control unit (100) determines whether the degree of change in the internal pressure ΔP within a certain period ΔT exceeds the predetermined range ΔP0. This determination operation by the control unit (100) corresponds to step S12 of the above-described embodiment.

[0077] In Modification Example 1, the pressure sensor in the internal space (S) can be used to determine refrigerant leakage. Also, the amount of refrigerant leaking into the internal space (S) can be estimated based on the degree of change in the internal pressure. For example, assuming the refrigerant filling amount of the internal refrigeration device (10) is about 6 kg, when the leakage amount is 1 kg (the leakage amount is 17% of the refrigerant filling amount), when the leakage amount is 3 kg (the leakage amount is 51% of the refrigerant filling amount), and when the leakage amount is 6 kg (the leakage amount is 100% of the refrigerant filling amount), let the pressures in the internal space (S) be X2 kPa, Y2 kPa, and Z2 kPa respectively (P2 < X2 < Y2 < Z2). When the internal pressure rises from P2 to X2 within a certain period, it can be known that the amount of refrigerant leaking into the internal space (S) is 1 kg. The same applies to Y2 and Z2.

[0078] (9-2) Modification Example 2 An index different from the refrigerant in Modification Example 2 is the current value of the motor (30a) that drives the internal fan (30). That is, the first sensor (51) in Modification Example 2 is a current sensor that detects the current value of the motor (30a) that drives the internal fan (30). When refrigerant leaks into the internal space (S), the density of the gas in the internal space (S) increases. Therefore, the operating load of the internal fan (30) increases, and the current value flowing through the motor (30a) rises. Utilizing this, the control unit (100) in Modification Example 2 determines that there is refrigerant leakage in the internal space (S) when the refrigerant sensor (50) detects refrigerant leakage and the current sensor detects that the degree of change in the current value of the motor (30a) is outside a predetermined range.

[0079] The degree of change in the current value indicates the degree of increase in the current value of the indoor fan motor (30a) over a certain period ΔT. For example, assuming the certain period ΔT is 1 minute, a predetermined range ΔE0 is set as the range within which the current value of the motor (30a) is normally expected to increase when no refrigerant leaks into the indoor space (S) during this 1 minute. When the current sensor detects that the increase (ΔE) in the current value of the motor (30a) in the indoor space (S) over 1 minute exceeds the predetermined range ΔE0, it is presumed that the refrigerant gas has leaked into the indoor space (S). For example, ΔE represents the difference between the current value E1 a certain period ago (e.g., 1 minute ago) and the current current value E2 (E2 > E1).

[0080] In this way, the control unit (100) determines whether the degree of change ΔE in the current value of the indoor fan motor (30a) over a certain period ΔT exceeds the predetermined range ΔE0. This determination operation by the control unit (100) corresponds to step S12 of the above embodiment.

[0081] From the above, in Modification 2, the current sensor that detects the current value of the indoor fan motor (30a) can be used for determining refrigerant leakage. Also, the current value of the motor (30a) may be set based on the amount of refrigerant gas leaking into the indoor space (S). Thereby, by measuring the current value of the motor (30a), the amount of refrigerant leaked into the indoor space (S) can be estimated.

[0082] (9-3) Modification 3 An index different from the refrigerant in Modification 3 is the pressure of the refrigerant flowing through the refrigerant circuit (R). That is, the first sensor (51) in Modification 3 is a refrigerant pressure sensor that detects the pressure of the refrigerant flowing through the refrigerant circuit (R). When refrigerant leaks from the refrigerant piping or the indoor heat exchanger (29), the pressure of the refrigerant in the refrigerant circuit (R) decreases. Utilizing this, the control unit (100) in Modification 3 determines refrigerant leakage in the indoor space (S) when the refrigerant sensor (50) detects refrigerant leakage and the refrigerant pressure sensor detects that the degree of change in the pressure of the refrigerant flowing through the refrigerant circuit (R) is outside the predetermined range. There is no particular limitation on the position where the refrigerant pressure sensor is provided, but in Modification 3, it is provided in the refrigerant piping in the refrigerant circuit (R).

[0083] The degree of change in the refrigerant pressure indicates the degree of pressure drop of the refrigerant in the refrigerant circuit (R) over a certain period of time ΔT. For example, assuming that the certain period of time ΔT is 1 minute, the range in which the refrigerant pressure of the refrigerant circuit (R) is expected to drop when no refrigerant leaks into the indoor space (S) within this 1 minute is a predetermined range ΔP R0 Let it be. The degree of pressure drop ΔP of the refrigerant in the refrigerant circuit (R) within 1 minute R is the predetermined range ΔP R0 When the pressure sensor detects that it has exceeded, it is presumed that the refrigerant gas has leaked into the indoor space (S). For example, ΔP R is the refrigerant pressure P a certain period before the present (for example, 1 minute before) R1 and the current refrigerant pressure P R2 (P R2 < P R1 ).

[0084] Thus, the control unit (100) determines whether the degree of change ΔP in the refrigerant pressure of the refrigerant circuit (R) over a certain period of time ΔT R exceeds the predetermined range ΔP R0 . This determination operation by the control unit (100) corresponds to step S12 of the above embodiment.

[0085] From the above, in Modification 3, the refrigerant pressure sensor can be used to determine refrigerant leakage in the indoor space (S). Also, the value of the refrigerant pressure in the refrigerant circuit (R) may be set based on the amount of refrigerant gas leaking into the indoor space (S). Thereby, the amount of refrigerant leaked into the indoor space (S) can be estimated by measuring the refrigerant pressure in the refrigerant circuit (R).

[0086] (9-4) Modification 4 The indoor refrigeration device (10) of Modification 4 does not have a refrigerant sensor (50) and has a first sensor (51). That is, in Modification 4, only the first sensor (51) is used to detect the refrigerant leaking into the indoor space (S). The first sensor (51) may be any of the sensors in the above-described embodiment and Modifications 1 to 3. The first sensor (51) of Modification 4 is a humidity sensor (51). In Modification 4, only the humidity sensor (51) is used to detect the refrigerant leakage in the indoor space (S). The operation of the control unit (100) of Modification 4 will be described with reference to FIG. 7.

[0087] In step S21, the control unit (100) determines whether it has detected that the degree of change ΔRH in the humidity of the indoor space (S) by the humidity sensor (51) is outside a predetermined range ΔRH0. If it is determined that the degree of decrease ΔRH in the humidity of the indoor space (S) has exceeded the predetermined range ΔRH0 (YES in step S21), step S22 is executed. If it is determined that the degree of decrease ΔRH in the humidity of the indoor space (S) has not exceeded the predetermined range ΔRH0 (NO in step S21), step S21 is executed again. The degree of change ΔRH in humidity and the predetermined range ΔRH0 are as described in the above embodiment.

[0088] In step S22, the control unit (100) outputs to the notification unit (60) that refrigerant gas is leaking into the indoor space (S).

[0089] In step S23, the control unit (100) notifies the user by alarm or display from the notification unit (60) that refrigerant gas is leaking.

[0090] Since the absorption wavelength range of miscellaneous gases such as ethylene gas in the infrared region and the absorption wavelength range of water molecules are different as described above, the humidity sensor (51) can suppress the misdetection of water molecules and miscellaneous gases. Therefore, by using the humidity sensor (51) instead of the refrigerant sensor (50), the refrigerant leaking into the indoor space (S) can be detected. Thereby, the humidity sensor (51) can be used for both measuring the humidity of the indoor space (S) and detecting the leaked refrigerant.

[0091] (10) Other embodiments Regarding the above-described embodiment or each of the above-described modifications, the following configuration may also be adopted.

[0092] The container (1) may be used not only for sea transportation but also for land transportation. Further, the refrigerated storage (1) may not be a container. The refrigerated storage (1) may be a stationary refrigerated warehouse installed on land.

[0093] There is no particular limitation on the sensor method of the first sensor (51). The first sensor (51) may be an NDIR method, a semiconductor method, or a thermal conductivity method. It is preferable that the first sensor (51) is not a sensor that causes false detection (cross-sensitivity) with miscellaneous gases (such as ethylene gas) that can be generated in the internal space (S) other than the refrigerant gas.

[0094] In the above modification 1, the first sensor (51) for detecting a gas component may be an ethylene gas sensor for detecting ethylene gas. In this case, the first sensor (51) is not a sensor of the NDIR method, and the refrigerant filled in the internal refrigeration device (10) may be a refrigerant having "-CH groups" in its molecular structure (for example, R32, R1234yf). This is because ethylene also has "-CH groups", so in the case of an NDIR method sensor, the absorption wavelength regions of ethylene gas having the same "-CH groups" and the refrigerant gas (for example, R32, R1234yf) overlap, making it difficult to distinguish and detect both, and the detection accuracy of the refrigerant gas cannot be improved. The ethylene gas sensor is used, for example, for managing the ripening state of fresh produce such as bananas that generate ethylene gas among the stored items in the storage space (3). In this way, by also using the ethylene gas sensor for determining refrigerant leakage, there is no need to provide a new sensor for determining refrigerant leakage, and the number of parts can be reduced.

[0095] In the above Modification Example 1, the first sensor (51) may be an oxygen sensor that detects oxygen in the storage space (S). The oxygen sensor is, for example, of the semiconductor type. The oxygen concentration in the storage space (S) decreases according to the amount of refrigerant leaked into the storage space (S). Utilizing this, the control unit (100) determines the refrigerant leakage in the storage space (S) based on the detection results of the refrigerant sensor (50) and the oxygen sensor. Also in this case, according to Boyle - Charles' law, the oxygen concentration (ppm) in the storage space (S) can be calculated according to the amount of refrigerant leakage (kg) into the storage space (S). Thereby, the refrigerant leakage can be determined by the degree of decrease from the oxygen concentration in the storage space (S) or the oxygen concentration in the atmosphere, and the amount of refrigerant leakage can also be determined. The oxygen sensor is provided, for example, in a container (1) equipped with an adjustment device (not shown) for adjusting the composition of the air in the storage space (S). The adjustment device adjusts the outside air to a predetermined composition and supplies the adjusted air to the storage space (S). The adjustment device adjusts the composition of the air in the storage space (3) in order to maintain the freshness of the stored items (especially fruits and vegetables) stored in the storage space (3). The oxygen sensor is used for detecting whether the oxygen concentration in the storage space (3) has reached the target concentration by the operation of the adjustment device, or whether the oxygen concentration in the storage space (3) has returned to the atmospheric concentration after the adjustment device stops, etc. By also using such an oxygen sensor for determining refrigerant leakage, there is no need to provide a new sensor for determining refrigerant leakage, and the number of components can be reduced.

[0096] In the above-described Modification 1, the first sensor (51) may be a carbon dioxide sensor that detects carbon dioxide in the storage space (S). The carbon dioxide sensor is, for example, of the NDIR type. The carbon dioxide concentration in the storage space (S) decreases according to the amount of refrigerant leaked into the storage space (S). Utilizing this, the control unit (100) determines the leakage of the refrigerant in the storage space (S) based on the detection results of the refrigerant sensor (50) and the carbon dioxide sensor. Also in this case, according to Boyle's law, the carbon concentration (ppm) in the storage space (S) can be calculated according to the amount of refrigerant leakage (kg) into the storage space (S). Thereby, the refrigerant leakage can be determined by the degree of decrease from the carbon dioxide concentration in the storage space (S) or the carbon dioxide concentration in the atmosphere, and the amount of refrigerant leakage can be determined. The carbon dioxide sensor is provided, for example, in the container (1) provided with the above-described adjustment device. By also using such a carbon dioxide sensor for determining refrigerant leakage, there is no need to provide a new sensor for determining refrigerant leakage, and the number of parts can be reduced.

[0097] In the above-described embodiment, when the control unit (100) detects refrigerant leakage by the refrigerant sensor (50) and detects that the concentration of the gas in the storage space (S) is outside a predetermined range by the first sensor (51), the control unit (100) may determine the refrigerant leakage in the storage space (S). The predetermined range indicates the normally assumed range of the gas concentration in the storage space (S) when no refrigerant leaks. That is, when the refrigerant sensor (50) detects refrigerant leakage and the gas concentration in the storage space (S) exceeds the predetermined range, the refrigerant leakage in the storage space (S) may be determined.

[0098] In the above Modification Example 1, when the control unit (100) detects refrigerant leakage by the refrigerant sensor (50) and detects that the pressure of the gas in the storage space (S) is outside the predetermined range by the first sensor (51), it may determine refrigerant leakage in the storage space (S). The predetermined range indicates the normally assumed range of the internal pressure of the storage space (S) when no refrigerant leakage occurs. That is, when the refrigerant sensor (50) detects refrigerant leakage and the pressure of the air in the storage space (S) exceeds the predetermined range, it may determine refrigerant leakage in the storage space (S).

[0099] In the above Modification Example 2, when the control unit (100) detects refrigerant leakage by the refrigerant sensor (50) and detects that the current value of the motor (30a) is outside the predetermined range by the first sensor (51), it may determine refrigerant leakage in the storage space (S). The predetermined range indicates the normally assumed range of the current value of the motor (30a) when no refrigerant leakage occurs. That is, when the refrigerant sensor (50) detects refrigerant leakage and the current value of the motor (30a) exceeds the predetermined range, it may determine refrigerant leakage in the storage space (S).

[0100] In the above Modification Example 3, when the control unit (100) detects refrigerant leakage by the refrigerant sensor (50) and detects that the pressure of the refrigerant flowing through the refrigerant circuit (R) is outside the predetermined range by the first sensor (51), it may determine refrigerant leakage in the storage space (S). The predetermined range indicates the normally assumed range of the refrigerant pressure in the refrigerant circuit (R) when no refrigerant leakage occurs. That is, when the refrigerant sensor (50) detects refrigerant leakage and the refrigerant pressure in the refrigerant circuit (R) exceeds the predetermined range, it may determine refrigerant leakage in the storage space (S).

[0101] In the above Modification Example 4, when the control unit (100) detects that the relative humidity of the storage space (S) is outside the predetermined range, it may determine refrigerant leakage in the storage space (S). The predetermined range indicates the normally assumed range of the humidity of the storage space (S) when no refrigerant leakage occurs.

[0102] In the above Modification 3, the first sensor (51) may be a refrigerant temperature sensor that detects the temperature of the refrigerant flowing through the refrigerant circuit (R). Since the refrigerant pressure can be obtained based on the refrigerant temperature in the refrigerant circuit (R), it is possible to determine the degree of change in the refrigerant temperature or that refrigerant gas is leaking from the refrigerant circuit (R) due to the refrigerant temperature. Specifically, when the control unit (100) detects refrigerant leakage by the refrigerant sensor (50) and also detects that the degree of change in the temperature of the refrigerant flowing through the refrigerant circuit (R) or the refrigerant temperature is outside a predetermined range by the refrigerant temperature sensor, it determines refrigerant leakage in the storage space (S).

[0103] In the above Modification 3, the first sensor (51) may be a sensor that detects an index indicating the pressure or temperature of the refrigerant flowing through the refrigerant circuit (R).

[0104] In the above embodiment and each modification, the order of step S11 and step S12 may be reversed. That is, after detecting in step S12 by the first sensor (51) that the above-mentioned change rate is outside the predetermined range (YES in step S12), the determination of refrigerant detection by the refrigerant sensor (50) in step S11 may be performed.

[0105] In the above embodiment and each modification, step S11 and step S12 may be performed simultaneously.

[0106] In the above-described embodiments and each modification, there is no particular limitation on how to obtain the "degree of change". The degree of change may indicate how much it has changed from a certain reference value regardless of a certain period. For example, the degree of change may be a change rate. The change rate indicates the ratio of the change with respect to a predetermined reference value. For example, when the first sensor (51) is a humidity sensor, taking the reference value of the relative humidity in the storage space (S) (for example, 50% RH) as the reference humidity and the relative humidity when the refrigerant leaks into the storage space (S) as the first humidity, the change rate can be defined as the ratio of the first humidity to the reference humidity. Since the value of the first humidity varies depending on the refrigerant leakage amount, by obtaining such a change rate, it is possible to determine the refrigerant leakage and also estimate the refrigerant leakage amount. Further, when the first sensor (51) is an oxygen sensor, the reference value of the oxygen concentration in the storage space (S) is the oxygen concentration in the atmosphere, and when the first sensor (51) is a carbon dioxide sensor, the reference value of the carbon dioxide concentration in the storage space (S) is the carbon dioxide concentration in the atmosphere.

[0107] In step S12 of the above-described embodiment, a plurality of fixed periods may be set. For example, assume that the fixed periods are set to 1 minute, 1.5 minutes, and 3 minutes. Different predetermined ranges ΔRH0 are provided for each of these fixed periods, and when the degree of humidity change ΔRH in any of the fixed periods falls outside the predetermined range ΔRH0, it may be determined as YES in step S12. By providing a plurality of such predetermined periods in this way, the accuracy of refrigerant leakage detection can be improved.

[0108] The storage space (S) may be the space inside the container (1), and for example, it may be only the storage space (3).

[0109] As described above, the embodiments and modifications have been explained, but it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims. Also, the above embodiments and modifications may be appropriately combined or replaced as long as the functions of the subject of the present disclosure are not impaired. The above descriptions such as "first", "second",... are used to distinguish the phrases to which these descriptions are given, and do not limit even the number and order of those phrases.

Industrial Applicability

[0110] As described above, the present disclosure is useful for in - storage refrigeration devices and refrigerated storage cabinets.

Explanation of Reference Numerals

[0111] 1 Container (refrigerated storage cabinet) 10 In - storage refrigeration device 30 In - storage fan 30b In - storage fan motor (motor) 50 Refrigerant sensor 51 First sensor 100 Control unit R Refrigerant circuit S In - storage space

Claims

1. An internal refrigeration device that cools an internal space (S) using a refrigerant circuit (R) that performs a refrigeration cycle, a refrigerant sensor (50) for detecting a leak of a refrigerant in the internal space (S); a first sensor (51) for detecting an indicator different from the refrigerant; and a control unit (100) that determines whether or not a refrigerant is leaking from the internal space (S) based on detection results of the refrigerant sensor (50) and the first sensor (51). In-cabin refrigeration unit.

2. The first sensor (51) detects a gas component in the interior space (S), When the refrigerant sensor (50) detects a refrigerant leak and the first sensor (51) detects that the concentration of a gas component in the internal space (S) or the degree of change in the concentration is outside a predetermined range, the control unit (100) determines whether a refrigerant leaks in the internal space (S). The internal refrigeration device according to claim 1.

3. The first sensor (51) detects humidity, oxygen, or carbon dioxide in the interior space (S). The internal refrigeration device according to claim 2.

4. The first sensor (51) detects the pressure of the gas in the internal space (S), When the refrigerant sensor (50) detects a refrigerant leak and the first sensor (51) detects that the pressure of the gas in the internal space (S) or the degree of change in the pressure is outside a predetermined range, the control unit (100) determines whether a refrigerant leaks in the internal space (S). The internal refrigeration device according to claim 1.

5. The storage compartment further includes an interior fan (30) for circulating air in the interior space (S), The first sensor (51) detects a current value of a motor (30a) that drives the internal fan (30), When the refrigerant sensor (50) detects a refrigerant leak and the first sensor (51) detects that the current value of the motor (30a) or the degree of change in the current value is outside a predetermined range, the control unit (100) determines whether a refrigerant leak has occurred in the internal space (S). The internal refrigeration device according to claim 1.

6. The first sensor (51) detects the pressure or temperature of the refrigerant flowing through the refrigerant circuit (R); When the refrigerant sensor (50) detects a refrigerant leak and the first sensor (51) detects that an index indicating the pressure or temperature of the refrigerant flowing through the refrigerant circuit (R) or a degree of change in the index is outside a predetermined range, the control unit (100) determines whether a refrigerant leak has occurred in the internal space (S). The internal refrigeration device according to claim 1.

7. A refrigerated storage facility equipped with an internal refrigeration device according to any one of claims 1 to 6.

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