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 internal refrigeration device and a refrigerated storage cabinet. [Background technology]

[0002] The internal refrigeration device disclosed in Patent Document 1 includes a refrigerant sensor provided inside the container. The refrigerant sensor detects refrigerant gas leaking from the refrigerant circuit into the container. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-101327 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a refrigerated storage container such as the container of Patent Document 1, if miscellaneous gases are generated in the interior space of the container, the refrigerant sensor may erroneously detect the miscellaneous gases as refrigerant gas.

[0005] An object of the present disclosure is to provide an in-cabinet refrigeration device that suppresses erroneous detection of refrigerant leaking inside the cabinet. [Means for solving the problem]

[0006] The first aspect is 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 interior space (S); a first sensor (51) for detecting an indicator different from the refrigerant; The internal refrigeration device includes a control unit (100) that determines whether or not there is a refrigerant leakage in the internal space (S) based on detection results of the refrigerant sensor (50) and the first sensor (51).

[0007] The refrigerant sensor (50) alone may erroneously detect, for example, miscellaneous gases generated in the internal space (S) as refrigerant gas. In contrast, in the first aspect, the detection result of the first sensor (51) is used in addition to the detection result of the refrigerant sensor (50) to determine whether or not there is a refrigerant leak. By determining that the change in the internal environment detected by the first sensor (51) is due to refrigerant gas, erroneous detection of a refrigerant leak in the internal space (S) can be suppressed.

[0008] The second aspect is the first aspect, The first sensor (51) detects a gas component in the interior space (S), When the refrigerant sensor (50) detects a refrigerant leakage 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 the occurrence of a refrigerant leakage in the internal space (S).

[0009] In the second aspect, the first sensor (51) can be used to detect the gas components in the internal space (S) as well as to determine whether or not there is a refrigerant leak.

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

[0011] In the third aspect, a sensor of a type used for detecting humidity, oxygen, or carbon dioxide is unlikely to mistakenly detect an interference gas such as ethylene gas. By using such a sensor and the refrigerant sensor (50) to determine whether or not there is a refrigerant leak, the reliability of the determination of whether or not there is a refrigerant leak can be improved. In addition, such a sensor is already installed in the interior space (S), and therefore there is no need to install a new sensor.

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

[0013] In the fourth aspect, when the refrigerant leaks, the pressure of the gas in the internal space (S) increases. This change in the pressure of the gas in the internal space (S) can be used to determine whether or not there is a refrigerant leak.

[0014] The fifth aspect is the first aspect, 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 first sensor (51) detects a refrigerant leak and also 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 the occurrence of a refrigerant leak in the internal space (S).

[0015] In the fifth aspect, when refrigerant leaks into the internal space (S), the density of the gas composition in the internal space (S) increases. This increases the operating load of the internal fan (30) and the value of the current flowing through the motor (30a). This change in the current value can be used to determine whether refrigerant is leaking.

[0016] The sixth aspect is the first aspect, The first sensor (51) detects the pressure or temperature of the refrigerant flowing through the refrigerant circuit (R), When the first sensor (51) detects a refrigerant leak 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, the control unit (100) determines the occurrence of a refrigerant leak in the internal space (S).

[0017] In the sixth aspect, when refrigerant leaks from the refrigerant circuit (R), the pressure and temperature of the refrigerant in the refrigerant circuit (R) change. This change in the refrigerant pressure or refrigerant temperature in the refrigerant circuit (R) can be used to determine whether or not there is a refrigerant leak.

[0018] A seventh aspect is a refrigerated storage cabinet equipped with the internal refrigeration device according to any one of the first to sixth aspects. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a perspective view of an internal refrigeration device according to an embodiment, as viewed from the front. [Diagram 2] FIG. 2 is a vertical cross-sectional view of the internal refrigeration device. [Diagram 3] FIG. 3 is a piping diagram of the internal refrigeration unit. [Figure 4] FIG. 4 is a block diagram showing the relationship between the control unit of the internal refrigeration device and other devices. [Diagram 5] FIG. 5 is a flowchart showing the operation of the control unit to determine whether or not there is a refrigerant leak. [Figure 6] FIG. 6 is a table showing an example of the relationship between the amount of refrigerant leakage and the relative humidity. [Figure 7] FIG. 7 is a flowchart showing the operation of the control unit according to the fourth modification for determining whether or not there is a refrigerant leak. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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. Furthermore, each configuration of the embodiments, modifications, other examples, etc. described below can be combined or partially substituted within the scope in which the present invention can be implemented.

[0021] (1) Overall configuration of the container As shown in FIG. 1, an internal refrigeration system (10) is applied to a container (1). The container (1) is an example of a refrigerated storage facility (1). The container (1) is used for marine transportation. The container (1) is a refrigerated container that cools the air inside the container (1).

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

[0023] The container (1) has a container body (2) and an internal refrigeration device (10). The internal 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. Food, plants, and other stored items are stored in the storage space (3). The internal refrigeration device (10) cools the air in the storage space (3). A front opening (4) is formed in the front of the container body (2). The internal 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) Internal refrigeration unit The internal refrigeration device (10) has a casing (11). The casing (11) constitutes 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) separates an external space (5), which is the space outside the container body (2), from the storage space (3). The partition plate (13) is located on the back side (rear side) of the casing (11).

[0025] The internal refrigeration system (10) includes a refrigerant circuit (R) that performs a refrigeration cycle. The internal refrigeration system (10) includes, as devices disposed outside the refrigeration system, a compressor (25), an external heat exchanger (26), and an external fan (27). The internal refrigeration system (10) includes, as devices disposed inside the refrigeration system, an internal heat exchanger (29) and an internal 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 on the upper portion 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, the flat plate portion (12a) is provided with an inspection window (22) and a ventilation device (40). The inspection window (22) is disposed on the right side of the flat plate portion (12a). The ventilation device (40) is disposed on the left side of the flat plate portion (12a). The inspection window (22) is a transparent window through which the inside of the casing body (12) can be seen. The ventilation device (40) ventilates the storage space (3).

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

[0028] The casing body (12) is formed by stacking 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 interior of the container. Thus, the recess (12b) has a side wall (16a) of the external casing (16) and a side wall of the internal casing (18) that extend in the vertical direction. The side wall (16a) of the external casing (16) that extends in the vertical direction separates the external space (5) from 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 fiber-reinforced plastic (FRP). The heat insulating layer (17) is made of 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 recessed portion (12b). The partition plate (13) extends in the vertical direction so as to be spaced a predetermined distance from the rear surface of the recessed portion (12b). An air passage (19) through which the air inside the container flows is formed between the casing body (12) and the partition plate (13). An inlet (20) is formed between an upper end of the partition plate (13) and an upper wall (2a) of the container body (2). The inlet (20) connects the storage space (3) to the inlet end of the air passage (19). An outlet (21) is formed between a lower end of the partition plate (13) and a lower wall (2b) of the container body (2). The outlet (21) connects the storage space (3) to the outlet end of the air passage (19). Air flows in the vertical direction in the air passage (19). Specifically, air flows in the vertical direction in the air passage (19).

[0030] (2-3) External space components The external storage space (14) is provided with a compressor (25), an external heat exchanger (26), and an external fan (27). The compressor (25) is installed on the bottom plate (12c) of the casing (11). The compressor (25) is disposed toward the lower part of the external storage space (14). The compressor (25) is disposed toward the right of the external storage space (14).

[0031] The external fan (27) is located toward the upper part of the external storage space (14). The external fan (27) is driven by an external fan motor (27a). The external fan (27) is a propeller fan. As shown in FIG. 2, an external passage (28) through which outside air flows is formed behind the external fan (27).

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

[0033] (2-4) Components of the interior space An internal heat exchanger (29) and an internal fan (30) are provided in the air passage (19). The internal heat exchanger (29) and the internal fan (30) are provided in the internal storage space (15), which is a part of the air passage (19). The internal heat exchanger (29) is supported by the casing (11) so as to span the casing body (12) and the partition plate (13). The internal heat exchanger (29) is a fin-and-tube heat exchanger.

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

[0035] (2-5) Refrigerant circuit As shown in Fig. 3, the internal refrigeration system (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] In this embodiment, 2,3,3,3 tetrafluoropropene (hereinafter sometimes referred to as R1234yf refrigerant or R1234yf) is used as the refrigerant. The refrigerant may be difluoromethane (R32) or 1,3,3,3 tetrafluoropropene (R1234ze). The refrigerant may be a single refrigerant or a mixed refrigerant mixed with other refrigerants. The mixed refrigerant may be a refrigerant consisting of two kinds of refrigerants, 2,3,3,3 tetrafluoropropene (R1234yf) and difluoromethane (R32). The mixed refrigerant may be a refrigerant (R454C) consisting of 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 the highly flammable natural refrigerants propane (R290), methane (R50), ethane (R170), butane (R600), and isobutane (R600a). The refrigerant may also be the natural refrigerant carbon dioxide (CO 2 ) may also be used.

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

[0038] The compressor (25) compresses the sucked refrigerant. The compressor (25) discharges the compressed refrigerant. A discharge pipe (32) is connected to a discharge portion of the compressor (25). A suction pipe (33) is connected to a suction portion of the compressor (25). An accumulator (34) is provided in the suction pipe (33). The accumulator (34) is a container that stores liquid refrigerant.

[0039] The external heat exchanger (26) exchanges heat between the refrigerant flowing therethrough and the external air. A gas end of the external heat exchanger (26) communicates with a discharge pipe (32). A liquid end of the external heat exchanger (26) is connected to a liquid end of the internal heat exchanger (29) through a liquid pipe (35). The external heat exchanger (26) functions as a radiator (condenser) that radiates heat from the refrigerant to the air.

[0040] The expansion valve (31) is provided in the liquid pipe (35). The expansion valve (31) reduces the pressure of high-pressure refrigerant to low-pressure refrigerant. The expansion valve (31) is an electronic expansion valve whose opening is adjustable. A receiver (36) is provided in the liquid pipe (35) between the external heat exchanger (26) and the expansion valve (31). The receiver (36) is a container that stores excess refrigerant in the refrigerant circuit (R).

[0041] The internal heat exchanger (29) exchanges heat between the refrigerant flowing therethrough and the internal air. A gas end of the internal heat exchanger (29) communicates with the suction pipe (33). The internal heat exchanger (29) functions as an evaporator in which the refrigerant absorbs heat from the air.

[0042] The refrigerant circuit (R) has a bypass pipe (37). An inflow end of the bypass pipe (37) communicates with the discharge pipe (32), and an 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 internal heat exchanger (29), bypassing the external heat exchanger (26).

[0043] The refrigerant circuit (R) is provided with a first valve (38) and a second valve (39). The first valve (38) is provided between the discharge side of the compressor (25) and the gas end of the external heat exchanger (26), and downstream of the connection part 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 formed by solenoid on-off valves. The first valve (38) and the second valve (39) may be flow rate control valves whose opening degree is adjustable.

[0044] (2-6) Driving behavior The internal refrigeration system (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) is condensed in the external heat exchanger (26), reduced in pressure by the expansion valve (31), and evaporated in the internal heat exchanger (29). Air flowing out from the storage space (3) into the air passage (19) is cooled by the internal heat exchanger (29) functioning as an evaporator. The cooled air is sent to the storage space (3) (see the arrow in FIG. 2).

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

[0047] (3) Control section As shown in Fig. 4, the internal refrigeration device (10) includes a control unit (100). The control unit (100) controls the internal refrigeration device (10). The control unit (100) includes a microprocessor, an electric circuit, and an electronic circuit. The microprocessor includes a central processing unit (CPU), a memory, a communication interface, an analog input / output, and a contact input / output interface. The memory stores various programs executed by the CPU and data used by the programs.

[0048] The control unit (100) controls mechanical elements of the internal refrigeration unit (10). As shown in FIG. 4, the target value may be a value that can be arbitrarily set by a user of the internal refrigeration unit (10) via an operation unit (101). The operation unit (101) is configured with, for example, a touch panel, a remote controller, and a dip switch provided in the internal refrigeration unit (10). The operation unit (101) may be a communication terminal connected to the internal refrigeration unit (10) via a network. The target value does not necessarily have to be set by a user, and may be a value that is automatically determined by the control unit (100) depending on, for example, an operation mode or an operation condition.

[0049] (4) Refrigerant sensor As shown in Fig. 2 and Fig. 4, the internal refrigeration system (10) includes a refrigerant sensor (50). The refrigerant sensor (50) detects refrigerant leaked from the refrigerant circuit (R) inside the container (1). Specifically, the refrigerant sensor (50) detects refrigerant contained in the air flowing through the air passage (19) as an indicator. The refrigerant sensor (50) is disposed below the internal fan (30). Hereinafter, air containing leaked refrigerant and air not containing leaked refrigerant may be collectively referred to as air. The refrigerant sensor (50) will be described in detail later.

[0050] (5) Notification device As shown in Fig. 4, the internal refrigeration device (10) includes an alarm unit (60). The alarm unit (60) notifies a user of predetermined information. The alarm unit (60) includes a predetermined speaker or display. For example, when the control unit (100) determines that there is an abnormality in the internal refrigeration device (10) or the internal space (S), the alarm unit (60) issues an alarm from the speaker or displays the abnormality on the display.

[0051] (6) Problems with false positives in refrigerant sensors If the refrigerant (refrigerant gas) leaked into the internal space (S) and contained in the air flowing through the internal space (S) has similar properties to the miscellaneous gases generated in the internal space (S), the refrigerant sensor (50) may detect the miscellaneous gases as refrigerant gas. For example, a non-dispersive infrared (NDIR) type sensor detects specific gases by utilizing the fact that various gases absorb specific wavelengths in the infrared range. With this NDIR type refrigerant sensor, if the absorption wavelength range of the refrigerant gas and the absorption wavelength range of the miscellaneous gas overlap or 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 refrigerant gas.

[0052] Specifically, suppose that R1234yf or R32 is used as the refrigerant in the internal freezer and fruit that generates ethylene gas is stored in the internal space.The absorption wavelength peak of the refrigerant is around 3.3μm, and ethylene gas also has an absorption wavelength peak in the same vicinity, so with this combination of gases, an NDIR refrigerant sensor may not be able to distinguish and detect the ethylene gas generated by the fruit and the refrigerant gas that has leaked into the internal space.

[0053] In contrast, the internal refrigeration system (10) of this embodiment includes a first sensor (51) that detects an indicator different from the refrigerant. In other words, the first sensor (51) does not detect refrigerant leaking into the internal space (S), which is the indicator detected by the refrigerant sensor (50). The internal refrigeration system (10) of this embodiment determines whether or not refrigerant is leaking into the internal space (S) based on the detection results of the refrigerant sensor (50) and the first sensor (51). The first sensor (51) will be described in detail below.

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

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

[0056] Here, the humidity sensor (51) of this embodiment is of the NDIR type. Since the absorption wavelength peak of water molecules is around 2.7 μm, the infrared absorption wavelength region of water molecules is different from the infrared absorption wavelength region of the refrigerant (e.g., R1234yf or R32). Therefore, the NDIR type humidity sensor (51) can suppress erroneous detection of miscellaneous gases and water molecules.

[0057] For example, if the humidity sensor (51) detects a behavior different from a normally expected change in humidity, such as a sudden drop in humidity in the interior space, it can be assumed that this is not due to humidity but due to refrigerant leaking into the interior space (S). In this way, the interior refrigeration system (10) of the present embodiment utilizes the humidity sensor (51), which is less likely to erroneously detect other miscellaneous gases, to suppress erroneous detection of the refrigerant by the refrigerant sensor (50).

[0058] (7) Operation of the control unit The operation of detecting refrigerant gas by the control unit (100) will be described below with reference to Fig. 5. The control unit (100) determines whether or not there is a leakage of refrigerant in the internal space (S) based on the detection results of the refrigerant sensor (50) and the humidity sensor (51). R1234yf is used as the refrigerant.

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

[0060] In step S12, the control unit (100) determines whether or not the humidity sensor (51) has detected that the degree of change in humidity is outside a predetermined range. Here, the degree of change in humidity refers to the degree of decrease in humidity ΔRH in the internal space (S) during a certain period ΔT. For example, the certain period ΔT is set to one minute, and the range of humidity change (decrease) that is normally expected in the absence of refrigerant leakage into the internal space (S) during this one minute is set to the predetermined range ΔRH. 0 The decrease in humidity (ΔRH) in the interior space (S) in one minute is within a specified range ΔRH 0 If the humidity sensor (51) detects that the humidity exceeds the value, it can be inferred that the refrigerant gas has leaked into the interior space (S). For example, ΔRH is the relative humidity RH 1 and the current relative humidity RH 2 (RH 2 <RH 1 ) difference.

[0061] The degree of change in humidity in the interior space (S) may be calculated by a predetermined calculation. For example, the degree of change in humidity can be calculated using Boyle's law. If the air temperature in the interior space (S) is 25°C and the relative humidity is 50%, the volume V corresponding to the amount of refrigerant leakage (kg) is calculated as follows: R (m 3 ), volume V of the storage space (3) (m 3 ) and the saturated water vapor content RH in the storage space (3) with an air temperature of 25°C s (g / m 3 ) and the amount of water vapor in the storage space (3) with an air temperature of 25°C RH 25 (g / m 3 In this case, the humidity RH when the refrigerant leaks into the interior space (S) is RH = RH 25 / RH S ×V / (V+V R )...(Equation 1) holds. Based on Equation 1, ΔRH in a certain period ΔT can be calculated.

[0062] The fixed period ΔT is set arbitrarily. The fixed period ΔT may be set based on the items stored in the interior space (S), or may be set based on the region in which the container is installed, the season, and the transport route of the container. Based on the premise that humidity changes that are normally expected are relatively gradual, the shorter the fixed period ΔT, the easier it is to distinguish between changes due to humidity and changes due to leaked refrigerant.

[0063] The degree of change in humidity in the interior space (S) ΔRH is within a specified range ΔRH 0 If it is determined that the degree of change in humidity ΔRH in the interior space (S) exceeds the predetermined range ΔRH 0 If it is not determined that the leakage current has exceeded the threshold voltage (NO in step S12), it is considered that the refrigerant gas has not leaked into the internal space (S), and step S11 is executed again.

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

[0065] In step S14, the control section (100) notifies the user of the fact that refrigerant gas is leaking by means of an alarm or a display from the notification section (60).

[0066] In this embodiment, the amount of refrigerant leaking into the internal space (S) can be estimated based on the degree of change in humidity in the internal space (S). As shown in Fig. 6, the amount of refrigerant charged in the internal refrigeration device (10) is set to about 6 kg, and the relative humidity of the internal space (S) when the leakage amount is 1 kg (17% of the refrigerant charge amount), when the leakage amount is 3 kg (51% of the refrigerant charge amount), and when the leakage amount is 6 kg (100% of the refrigerant charge amount) is expressed as X 1 %, Y 1 %, Z 1 % (50%>X 1 >Y 2 >Z 1 ) The humidity in the storage space (S) changes from 50% to X% in a certain period of time.1 %, it can be assumed that 1 kg of refrigerant has leaked into the interior space (S). If the humidity in the interior space (S) changes from 50% to Y 1 %, it can be assumed that 3 kg of refrigerant is leaking into the storage space (S). 1 %, it can be assumed that 6 kg of refrigerant has leaked into the interior space (S).

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

[0068] The refrigerant sensor (50) may detect miscellaneous gases such as ethylene gas that may be generated in the internal space (S). In this embodiment, the detection result of the first sensor (51) is used in addition to the detection result of the refrigerant sensor (50) to determine whether or not a refrigerant leak has occurred. In this way, when the refrigerant sensor (50) detects a refrigerant and the change in the environment of the internal space (S) detected by the first sensor (51) is due to a refrigerant leak, it can be determined that a refrigerant is leaking into the internal space (S). In this way, false detection of a refrigerant leak can be suppressed and the accuracy of detection of a refrigerant leak can be improved.

[0069] (8-2) Feature 2 The control unit (100) of the internal refrigeration device (10) of this embodiment determines the occurrence of refrigerant leakage in the internal space (S) when the refrigerant sensor (50) detects refrigerant leakage and the first sensor (51) detects that the degree of change in concentration of the gas component in the internal space (S) is outside a predetermined range. In this way, the first sensor (51) can be used not only to detect the gas component in the internal space (S) but also to determine the occurrence of refrigerant leakage.

[0070] (8-3) Feature 3 The first sensor (51) of the internal refrigeration device (10) of this embodiment is a humidity sensor that detects the humidity in the internal space (S). The humidity sensor (51) detects water vapor (water molecules) and is not likely to detect other miscellaneous gases. By using the humidity sensor (51) in this manner to determine whether or not there is a refrigerant leak, the accuracy of the determination of whether or not there is a refrigerant leak can be improved. The humidity sensor (51) is also used to maintain the freshness (humidity control) of the items stored in the accommodation space (3) of the container (1). By using the humidity sensor (51) in this manner also to determine whether or not there is a refrigerant leak, it is not necessary to provide a new sensor just for determining whether or not there is a refrigerant leak, and the number of parts can be reduced.

[0071] (9) Variations Modifications of the above embodiment will be described below, with the configurations different from those of the above embodiment being described below.

[0072] (9-1) Variation 1 The indicator that differs from the refrigerant in the first modification is the pressure of the gas in the internal space (S). That is, the first sensor (51) in the first modification is a pressure sensor that detects the pressure of the gas in the internal space (S). When refrigerant gas leaks into the internal space (S), the pressure of the gas in the internal space (S) increases by the amount of the leaked refrigerant gas. Using this, the control unit (100) in the first modification determines the leakage of refrigerant in the internal space (S) based on the detection results of the refrigerant sensor (50) and the pressure sensor.

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

[0074] The degree of change in the internal pressure indicates the degree of pressure rise of the gas in the internal space (S) in a certain period ΔT. For example, the certain period ΔT is one minute, and the range of the internal pressure that is normally assumed to decrease if no refrigerant leaks into the internal space (S) during this one minute is called the predetermined range ΔP. 0 The degree of increase in the internal pressure of the internal space (S) in one minute ΔP is within a predetermined range ΔP 0 If the pressure sensor detects that the pressure exceeds the threshold, it is assumed that the refrigerant gas has leaked into the interior space (S). For example, ΔP indicates the difference between the interior pressure P1 from a certain period of time ago (for example, 1 minute ago) and the current interior pressure P2 (P2>P1).

[0075] The degree of change in the internal pressure may be calculated by a predetermined calculation. For example, the degree of change in the internal pressure can be calculated using Boyle's law. Specifically, the internal pressure P1 due to the refrigerant leakage, the volume V1 of the internal space, the standard atmospheric pressure P2 (1 atmospheric pressure), and the volume V of the leaked refrigerant are calculated as follows: R For P1=(V1+V R )×P2 / V1…(Equation 2) holds true.

[0076] By substituting known values ​​for V1 and P2 in Equation 2, the volume of the leaked refrigerant, V R In this manner, in the first modification, the control unit (100) determines whether the degree of change ΔP in the internal pressure during a certain period ΔT falls within a predetermined range ΔP 0 This determination operation by the control unit (100) corresponds to step S12 in the above embodiment.

[0077] In the first modification, a pressure sensor in the internal space (S) can be used to determine whether or not there is a refrigerant leak. 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 that the amount of refrigerant charged in the internal refrigeration device (10) is about 6 kg, the pressures in the internal space (S) when the leakage amount is 1 kg (17% of the refrigerant charge amount), when the leakage amount is 3 kg (51% of the refrigerant charge amount), and when the leakage amount is 6 kg (100% of the refrigerant charge amount) are expressed as X, 2kPa, Y 2 kPa, Z 2 kPa (P2 <X 2 <Y 2 <Z 2 ) If the pressure inside the chamber changes from P2 to X within a certain period of time, 2 When the temperature rises to 100°C, the amount of refrigerant leaked into the interior space (S) is 1 kg. 2 and Z 2 The same is true for.

[0078] (9-2) Variation 2 The indicator different from the refrigerant in the second modification is the current value of the motor (30a) that drives the internal fan (30). That is, the first sensor (51) in the second modification 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. This increases the operating load of the internal fan (30), and the current value flowing through the motor (30a) increases. Using this, the control unit (100) in the second modification determines the leakage of refrigerant in the internal space (S) when the refrigerant sensor (50) detects the leakage of refrigerant 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 internal fan motor (30a) during a certain period ΔT. For example, the certain period ΔT is set to one minute, and the range within which the current value of the motor (30a) typically increases when no refrigerant leaks into the internal space (S) during this one minute is defined as a predetermined range ΔE 0 The increase (ΔE) in the current value of the motor (30a) of the interior space (S) in one minute is within a predetermined range ΔE 0 If the current sensor detects that the current exceeds the threshold, it is assumed that the refrigerant gas has leaked into the interior space (S). For example, ΔE indicates the difference between the current value E1 from a certain period of time ago (for example, 1 minute ago) and the current current value E2 (E2>E1).

[0080] In this manner, the control unit (100) determines whether the degree of change ΔE in the current value of the internal fan motor (30a) during a certain period ΔT is within a predetermined range ΔE 0 This determination operation by the control unit (100) corresponds to step S12 in the above embodiment.

[0081] As described above, in the second modification, a current sensor that detects the current value of the internal fan motor (30a) can be used to determine whether or not refrigerant leakage has occurred. Also, the current value of the motor (30a) may be set based on the amount of refrigerant gas leaking into the internal space (S). In this way, the amount of refrigerant leaking into the internal space (S) can be estimated by measuring the current value of the motor (30a).

[0082] (9-3) Variation 3 The indicator different from that of the third modification is the pressure of the refrigerant flowing through the refrigerant circuit (R). That is, the first sensor (51) of the third modification 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 internal heat exchanger (29), the pressure of the refrigerant in the refrigerant circuit (R) decreases. Using this, the control unit (100) of the third modification determines the leakage of refrigerant in the internal space (S) when the refrigerant sensor (50) detects the leakage of refrigerant 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 a predetermined range. There is no particular limitation on the position at which the refrigerant pressure sensor is provided, but in the third modification, the refrigerant pressure sensor 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) in a certain period ΔT. For example, the certain period ΔT is set to 1 minute, and the range of the refrigerant pressure drop in the refrigerant circuit (R) that is assumed when no refrigerant leaks into the interior space (S) during this 1 minute is defined as a predetermined range ΔP R0 The degree of decrease in refrigerant pressure in the refrigerant circuit (R) in one minute is ΔP R is within the specified range ΔP R0 If the pressure sensor detects that the pressure exceeds ΔP, it is assumed that the refrigerant gas has leaked into the interior space (S). Ris the refrigerant pressure P from a certain period of time ago (for example, 1 minute ago) R1 and the current refrigerant pressure P R2 (P R2 <P R1 ) indicates the difference.

[0084] In this manner, the control unit (100) calculates the degree of change ΔP of the refrigerant pressure in the refrigerant circuit (R) during a certain period ΔT. R is within the specified range ΔP R0 This determination operation by the control unit (100) corresponds to step S12 in the above embodiment.

[0085] As described above, in the third modification, the refrigerant pressure sensor can be used to determine refrigerant leakage in the internal 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 internal space (S). This makes it possible to estimate the amount of refrigerant leaking into the internal space (S) by measuring the refrigerant pressure in the refrigerant circuit (R).

[0086] (9-4) Variation 4 The internal refrigeration device (10) of the fourth modification does not have a refrigerant sensor (50) but has a first sensor (51). That is, in the fourth modification, refrigerant leaking into the internal space (S) is detected only by the first sensor (51). The first sensor (51) may be any of the sensors in the above embodiment and the first to third modifications. The first sensor (51) of the fourth modification is a humidity sensor (51). In the fourth modification, refrigerant leakage in the internal space (S) is detected only by the humidity sensor (51). The operation of the control unit (100) of the fourth modification will be described with reference to FIG. 7.

[0087] In step S21, the control unit (100) detects whether the degree of change in humidity ΔRH in the interior space (S) is within a predetermined range ΔRH 0 It is determined whether the humidity in the interior space (S) is outside the predetermined range ΔRH. 0 If it is determined that the humidity decrease ΔRH in the interior space (S) exceeds the predetermined range ΔRH 0If it is determined that the humidity does not exceed the predetermined range ΔRH (NO in step S21), step S21 is executed again. 0 is as described in the above embodiment.

[0088] In step S22, the control section (100) outputs to the notification section (60) a signal indicating that refrigerant gas is leaking into the internal space (S).

[0089] In step S23, the control section (100) notifies the user of the fact that refrigerant gas is leaking by means of an alarm or a display from the notification section (60).

[0090] As described above, the humidity sensor (51) has a wavelength range in the infrared region where ethylene gas and other miscellaneous gases have different absorption wavelengths, and therefore can suppress erroneous detection of water molecules and miscellaneous gases. Therefore, the humidity sensor (51) can detect refrigerant leaking into the internal space (S) without using the refrigerant sensor (50). This allows the humidity sensor (51) to be used both to measure the humidity in the internal space (S) and to detect leaking refrigerant.

[0091] (10) Other embodiments The above embodiment or each of the above modified examples may be configured as follows.

[0092] The container (1) may be used not only for marine transportation but also for land transportation. The refrigerated storage facility (1) does not have to be a container. The refrigerated storage facility (1) may be a stationary refrigerated warehouse installed on land.

[0093] The sensor type of the first sensor (51) is not particularly limited. The first sensor (51) may be an NDIR type, a semiconductor type, or a thermal conductivity type. It is preferable that the first sensor (51) is not a sensor that causes erroneous detection (cross sensitivity) with miscellaneous gases (such as ethylene gas) other than the refrigerant gas that may be generated in the interior space (S).

[0094] In the first modification, 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 an NDIR type sensor, and the refrigerant filled in the internal refrigeration device (10) need not be a refrigerant having a "-CH group" in its molecular structure (e.g., R32, R1234yf). This is because, since ethylene also has a "-CH group", in the case of an NDIR type sensor, the absorption wavelength ranges of ethylene gas having the same "-CH group" and refrigerant gas (e.g., R32, R1234yf) overlap, making it difficult to distinguish and detect the two, and thus making it difficult to improve the detection accuracy of the refrigerant gas. For example, when the stored items stored in the storage space (3) are fruits and vegetables that generate ethylene gas, such as bananas, the ethylene gas sensor is used to manage the ripening state of the fruits and vegetables. In this way, by using the ethylene gas sensor also for determining whether or not there is a refrigerant leak, there is no need to provide a new sensor for determining whether or not there is a refrigerant leak, and the number of parts can be reduced.

[0095] In the first modification, the first sensor (51) may be an oxygen sensor that detects oxygen in the internal space (S). The oxygen sensor is, for example, a semiconductor type. The oxygen concentration in the internal space (S) decreases according to the amount of refrigerant leaked into the internal space (S). Using this, the control unit (100) determines the leakage of refrigerant in the internal space (S) based on the detection results of the refrigerant sensor (50) and the oxygen sensor. In this case, too, the oxygen concentration (ppm) in the internal space (S) can be calculated according to the amount (kg) of refrigerant leaked into the internal space (S) by Boyle-Charles' law. This makes it possible to determine the leakage of refrigerant and the amount of refrigerant leakage based on the degree of decrease in the oxygen concentration in the internal space (S) or the oxygen concentration in the air. The oxygen sensor is provided, for example, in the container (1) that includes an adjustment device (not shown) that adjusts the composition of air in the internal space (S). The adjustment device adjusts the outside air to a predetermined composition and supplies the adjusted air to the internal 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 (particularly fruits and vegetables) stored in the storage space (3). The oxygen sensor is used to detect whether the oxygen concentration in the storage space (3) has reached a target concentration by operating the adjustment device, and whether the oxygen concentration in the storage space (3) has returned to the atmospheric concentration after the adjustment device is stopped. By using such an oxygen sensor also to determine refrigerant leaks, there is no need to install a new sensor to determine refrigerant leaks, and the number of parts can be reduced.

[0096] In the first modification, the first sensor (51) may be a carbon dioxide sensor that detects carbon dioxide in the internal space (S). The carbon dioxide sensor may be, for example, an NDIR type. The carbon dioxide concentration in the internal space (S) decreases according to the amount of refrigerant leaked into the internal space (S). Using this, the control unit (100) determines the leakage of refrigerant in the internal space (S) based on the detection results of the refrigerant sensor (50) and the carbon dioxide sensor. In this case, too, the carbon concentration (ppm) in the internal space (S) can be calculated according to the amount (kg) of refrigerant leaked into the internal space (S) by Boyle-Charles' law. This allows the leakage of refrigerant to be determined based on the degree of decrease in the carbon dioxide concentration in the internal space (S) from the carbon dioxide concentration in the air or the carbon dioxide concentration in the atmosphere, and also allows the amount of refrigerant leakage to be determined. The carbon dioxide sensor is provided, for example, in the container (1) that includes the above-mentioned adjustment device. By using such a carbon dioxide sensor also for determining the leakage of refrigerant, it is not necessary to provide a new sensor for determining the leakage of refrigerant, and the number of parts can be reduced.

[0097] In the above embodiment, the control unit (100) may determine that refrigerant leakage occurs in the internal space (S) when the refrigerant leakage is detected by the refrigerant sensor (50) and the first sensor (51) detects that the gas concentration in the internal space (S) is outside a predetermined range. The predetermined range indicates a range that is normally expected for the gas concentration in the internal space (S) when there is no refrigerant leakage. In other words, when the refrigerant leakage is detected by the refrigerant sensor (50) and the gas concentration in the internal space (S) exceeds the predetermined range, the control unit (100) may determine that refrigerant leakage occurs in the internal space (S).

[0098] In the above-described first modification, the control unit (100) may determine that refrigerant leakage occurs in the internal space (S) when the refrigerant sensor (50) detects that refrigerant leakage occurs and the first sensor (51) detects that the pressure of the gas in the internal space (S) is outside a predetermined range. The predetermined range indicates a normally expected range of the internal pressure in the internal space (S) when there is no refrigerant leakage. In other words, when the refrigerant leakage occurs and the refrigerant sensor (50) detects that refrigerant leakage occurs and the pressure of the air in the internal space (S) exceeds the predetermined range, the control unit (100) may determine that refrigerant leakage occurs in the internal space (S).

[0099] In the above-described second modification, the control unit (100) may determine the presence of refrigerant leakage in the internal space (S) when the refrigerant sensor (50) detects refrigerant leakage and the first sensor (51) detects that the current value of the motor (30a) is outside a predetermined range. The predetermined range refers to a normally expected range of the current value of the motor (30a) when there is no refrigerant leakage. In other words, the control unit (100) may determine the presence of refrigerant leakage in the internal space (S) when the refrigerant leakage is detected by the refrigerant sensor (50) and the current value of the motor (30a) exceeds the predetermined range.

[0100] In the third modification, the control unit (100) may determine that refrigerant leakage occurs in the internal space (S) when the refrigerant sensor (50) detects that refrigerant leakage occurs and the first sensor (51) detects that the pressure of the refrigerant flowing through the refrigerant circuit (R) is outside a predetermined range. The predetermined range refers to a normally expected range of the refrigerant pressure in the refrigerant circuit (R) when there is no refrigerant leakage. In other words, when the refrigerant leakage occurs and the refrigerant pressure in the refrigerant circuit (R) exceeds the predetermined range, the control unit (100) may determine that refrigerant leakage occurs in the internal space (S).

[0101] In the above-described fourth modification, the control unit (100) may determine the occurrence of refrigerant leakage in the internal space (S) when it is detected that the relative humidity of the internal space (S) is outside a predetermined range. The predetermined range indicates a normally expected range of humidity in the internal space (S) when there is no refrigerant leakage.

[0102] In the third modification, 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 calculated based on the refrigerant temperature in the refrigerant circuit (R), it is possible to determine that refrigerant gas is leaking from the refrigerant circuit (R) based on the degree of change in the refrigerant temperature or the refrigerant temperature. Specifically, when the refrigerant sensor (50) detects refrigerant leakage and the refrigerant temperature sensor 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, the control unit (100) determines that refrigerant is leaking in the interior space (S).

[0103] In the above-described third modification, the first sensor (51) may be a sensor that detects an indicator indicative of the pressure or temperature of the refrigerant flowing through the refrigerant circuit (R).

[0104] In the above embodiment and each modified example, the order of steps S11 and S12 may be reversed. That is, after the first sensor (51) detects in step S12 that the rate of change is outside the predetermined range (YES in step S12), it may be determined in step S11 whether the refrigerant sensor (50) has detected the refrigerant.

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

[0106] In the above embodiment and each modified example, there is no particular limitation on the method of calculating the "degree of change." The degree of change may indicate how much the value has changed from a certain reference value regardless of a certain period of time. For example, the degree of change may be a rate of change. The rate of change indicates a ratio of change to a predetermined reference value. For example, when the first sensor (51) is a humidity sensor, the reference value of the relative humidity of the internal space (S) (e.g., 50% RH) is defined as the reference humidity, and the relative humidity when the refrigerant leaks into the internal space (S) is defined as the first humidity, the rate of change 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 amount of refrigerant leakage, by calculating such a rate of change, it is possible to determine whether or not there is a refrigerant leakage and to estimate the amount of refrigerant leakage. When the first sensor (51) is an oxygen sensor, the reference value of the oxygen concentration in the internal 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 internal space (S) is the carbon dioxide concentration in the atmosphere.

[0107] In step S12 of the above embodiment, a plurality of fixed periods may be set. For example, the fixed periods may be set to 1 minute, 1.5 minutes, and 3 minutes. A different predetermined range ΔRH 0 If the degree of humidity change ΔRH during any given period falls outside the specified range ΔRH 0 In this case, the determination in step S12 may be YES. By providing a plurality of predetermined periods in this manner, the accuracy of refrigerant leakage detection can be improved.

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

[0109] Although the embodiments and modifications have been described above, it will be understood that various modifications of form and details are possible without departing from the spirit and scope of the claims. Furthermore, the above embodiments and modifications may be appropriately combined or substituted as long as the functions of the subject of this disclosure are not impaired. The descriptions "first", "second", ... described above are used to distinguish the words to which these descriptions are attached, and do not limit the number or order of the words. [Industrial Applicability]

[0110] INDUSTRIAL APPLICABILITY As described above, the present disclosure is useful for internal refrigeration devices and refrigerated storage cabinets. [Explanation of symbols]

[0111] 1 Container (refrigerated storage) 10. Internal refrigeration unit 30 Interior fan 30b Interior fan motor (motor) 50 Refrigerant Sensor 51 First Sensor 100 Control section R Refrigerant circuit S Interior 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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