JP2017067390A - Refrigeration system for storage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigeration system for a storage capable of preventing accumulation of a refrigerant by efficiently discharging the refrigerant leaking into the storage, to the outside of the storage.SOLUTION: A refrigeration system for a storage performing a cooling operation for cooling indoor air of the storage (1) is provided with an exhaust hose (42) connecting the inside and outside of the storage, and an exhaust valve (43) disposed in the exhaust hose (42), and is constituted to perform a storage operation for storing a leaking refrigerant into a prescribed storage container (41) disposed at a lower part with respect to an evaporator (24) in the storage, while stopping an operation of an inner fan (26), when the refrigerant of a refrigerant circuit (20) having a specific gravity larger than the air leaks in the storage, and to perform an exhausting operation to discharge the refrigerant stored in the storage container (41) to the outside of the storage by opening the exhaust valve (43) and restarting the operation of the inner fan (26) after the termination of the storage operation.SELECTED DRAWING: Figure 2

Description

    The present invention relates to a refrigeration system for a storage for cooling the internal air of the storage, and particularly relates to measures against refrigerant leakage.

    Conventionally, a refrigeration system including a refrigerant circuit that performs a refrigeration cycle by circulating a refrigerant has been used in order to cool air in a storage for storing food or the like (see, for example, Patent Document 1).

    By the way, the storage for freezing and refrigeration has a highly airtight structure in order to prevent intrusion of outside air. Therefore, when the refrigerant in the refrigerant circuit leaks into the storage, it is difficult for the leaked refrigerant to be discharged out of the storage and stays in the storage. If the refrigerant leaking into the warehouse in this way stays in the warehouse without being discharged out of the warehouse, there is a risk of various harmful effects.

    Specifically, in recent years, in order to prevent global warming, conversion to a refrigerant having a low global warming potential (GWP) has been demanded. For this type of refrigerant, for example, R32 (HFC32) is used. Some have slight flammability. When such a slightly flammable refrigerant is used, if the refrigerant leaks from the refrigerant circuit and stays in the warehouse, for example, when the door is opened for loading / unloading work, it stays and is concentrated. There is a risk that the slightly flammable refrigerant leaks out of the warehouse at once, and is ignited by an ignition source outside the warehouse such as a forklift.

    Moreover, propane may be used as a refrigerant with a low global warming potential. Propane is a highly flammable refrigerant that is even more flammable than R32 (HFC32), so if it leaks and stays in the cabinet, there is a very high risk of ignition, causing severe damage such as a fire in the cabinet. There is a fear.

    Furthermore, when carbon dioxide is used as a refrigerant, if it leaks from the refrigerant circuit and stays in the cabinet and is concentrated, there is a risk of adversely affecting the human body or the stored items in the cabinet.

    As described above, when the refrigerant in the refrigerant circuit leaks into the storage case, the refrigerant stays in the storage without being discharged out of the storage, which may cause various harmful effects. Therefore, when the refrigerant leaks, the inside air is discharged to the outside, and the leaked refrigerant is discharged together with the inside air so that the leaked refrigerant does not stay in the inside. Conceivable.

Japanese Patent Laid-Open No. 11-63690

    However, when the refrigerant leaks into the warehouse, the method of exhausting the air inside the warehouse outside the warehouse by discharging the leaked refrigerant together with the air inside the warehouse discharges the air inside the warehouse cooled by the refrigeration system. For this reason, when the discharge amount increases, the temperature of the internal air may increase.

    This invention is made in view of this point, The objective is related with the refrigeration system for storage, The refrigerant | coolant which leaked in the store | warehouse | chamber is discharged | emitted outside the store | warehouse | chamber efficiently, and it does not stay in the store | warehouse | chamber. There is.

    According to a first aspect of the present invention, a refrigerant circuit (20) that is provided in a storage (1) and performs a refrigeration cycle by circulating refrigerant, and air in the storage (1) is transferred to the refrigerant circuit (20). An internal fan (26) that circulates the internal air in the storage (1) so as to pass through the connected evaporator (24) and exchange heat with the refrigerant, and the storage (1 ) Refrigeration system for storage that performs cooling operation for cooling the internal air of the storage, and includes a communication path (42) that connects the inside of the storage and the outside of the storage, and an on-off valve provided in the communication path (42) ( 43), and the refrigerant in the refrigerant circuit (20) is a refrigerant having a specific gravity greater than that of air, and when the refrigerant in the refrigerant circuit (20) leaks into the warehouse, the internal fan (26) The storage operation of storing the refrigerant leaked by stopping the operation in a predetermined storage location (41) provided below the evaporator (24) in the storage is performed. After the end of the distilling operation, the on-off valve (43) is opened and the operation of the internal fan (26) is restarted to perform an exhaust operation for discharging the refrigerant stored in the storage location (41) to the outside. It is configured.

    In 1st invention, when the refrigerant | coolant of a refrigerant circuit (20) leaks in the store | warehouse | chamber, it does not perform the exhaust operation which discharge | releases a refrigerant | coolant immediately outside a store | warehouse | chamber, but stops the operation | movement of the fan (26) in a store | chamber. Storage operation is performed. When the operation of the internal fan (26) is stopped, the refrigerant leaking into the internal compartment has a specific gravity greater than that of the air, so it falls and has a predetermined storage location (41) provided below the evaporator (24). It is stored in. By performing the exhaust operation after the end of such a storage operation, the refrigerant that has leaked into the warehouse is collectively discharged in a state where it is stored to some extent in the storage location (41).

    According to a second aspect, in the first aspect, the first state in which the air blown from the internal fan (26) is guided in the direction of circulation in the internal space, and the refrigerant stored in the storage location (41) is outside the internal space. A wind guide mechanism (44) configured to switch to a second state in which at least a part of the blown air of the internal fan (26) is led to the storage location (41) so as to be discharged to The air guide mechanism (44) is switched to the first state when the cooling operation is performed, and is switched to the second state when the exhaust operation is performed.

    In the second invention, the flow direction of the blown air of the internal fan (26) is switched by the wind guide mechanism (44). Specifically, when the cooling operation is performed, the air guide mechanism (44) is switched to the first state that guides the air blown from the internal fan (26) in the direction of circulation in the internal storage. Thereby, the in-compartment air cooled by the refrigerant in the evaporator (24) circulates in the interior. On the other hand, when performing the exhaust operation, the air guide mechanism (44) is switched to the second state in which at least part of the air blown from the internal fan (26) is guided to the storage location (41). Thereby, the refrigerant | coolant stored by the storage location (41) is discharged | emitted outside a warehouse through a communicating path (41) with the blowing air of the fan (26) in a warehouse.

    According to a third aspect of the present invention, in the first or second aspect, the communication path (42) is provided across the inside and the outside of the warehouse, and the check portion that prevents the outside air from flowing into the warehouse. A drain pipe (33) for discharging condensed water generated in the evaporator (24) to the outside of the warehouse, and the drain pipe (33) so as to bypass the check part (35). The on-off valve (43) is provided in the bypass passage (36).

    In the third invention, in the exhaust operation, when the on-off valve (43) is opened and the operation of the internal fan (26) is resumed, the refrigerant leaked into the internal storage and stored in the storage location (41) becomes the internal air At the same time, it flows into the drain pipe (33), passes through the bypass passage (36), bypasses the check portion (35), and is discharged to the outside.

    According to a fourth invention, in any one of the first to third inventions, when the refrigerant concentration in the air at the storage location (41) exceeds a predetermined upper limit concentration, the storage operation is terminated and the exhaust operation is performed. Configured to do.

    In the fourth invention, when a certain amount of refrigerant accumulates in the storage location (41) and the refrigerant concentration in the air at the storage location (41) exceeds a predetermined upper limit concentration, the storage operation is terminated and the exhaust operation is performed.

    According to a fifth invention, in any one of the first to third inventions, when a predetermined time elapses from a start time of the storage operation, the storage operation is terminated and the exhaust operation is performed.

    In the fifth aspect of the invention, when a predetermined time has elapsed from the start of the storage operation, it is assumed that a certain amount of refrigerant has accumulated in the storage location (41), and the storage operation is terminated and the exhaust operation is performed.

    According to 1st invention, when the refrigerant | coolant of a refrigerant circuit (20) leaks in a store | warehouse | chamber, it does not immediately perform the exhaust operation which discharge | releases a refrigerant | coolant outside a store | warehouse | chamber, but operates the fan (26) in a store | warehouse | chamber. The refrigerant that stopped and leaked was decided to be stored after the storage operation for storing the refrigerant in the predetermined storage location (41). Thereby, when a refrigerant | coolant leaks in a store | warehouse | chamber, the leaked coolant can be collectively discharged | emitted in the state stored in the storage location (41) to some extent. Therefore, compared with the case where the exhaust operation is performed immediately when the refrigerant leaks into the warehouse, the refrigerant leaking into the warehouse can be efficiently discharged outside the warehouse without exhausting the air in the warehouse. . Accordingly, it is possible to suppress an increase in the temperature of the air in the storage accompanying the discharge of the refrigerant leaking into the storage.

    Further, according to the second aspect of the invention, the wind guide mechanism (44) for switching the flow direction of the blown air from the internal fan (26) is provided, and when the cooling operation is performed, the wind guide mechanism (44) is the first. In the evaporator (24), the air in the warehouse cooled by the refrigerant is circulated in the warehouse, and when the exhaust operation is performed, the air guide mechanism (44) is switched to the second state to store the storage location ( It was decided that the refrigerant stored in 41) would be discharged to the outside using the dynamic pressure of the air blown from the internal fan (26). As a result, during the cooling operation, the refrigerant stored in the storage location (41) is used during the exhaust operation without disturbing the air circulation in the warehouse, and the dynamic pressure of the air blown from the internal fan (26) is used. And can be smoothly discharged to the outside.

    Further, according to the third invention, the existing drain pipe (33) is used as the communication path (42) for discharging the refrigerant leaking into the warehouse to the outside. Specifically, a bypass passage (36) that bypasses the check portion (35) is provided in the existing drain pipe (33), and an open / close valve (43) is provided in the bypass passage (36). By providing the bypass passage (36) and the on-off valve (43) in this way and using the existing drain pipe (33), the refrigerant can be discharged without providing a new passage connecting the outside and the inside of the warehouse. It is possible to easily form the path to be performed.

    According to the fourth invention, the end point of the storage operation and the start point of the exhaust operation are determined from the refrigerant concentration in the air at the storage location (41). Therefore, since the exhaust operation can be performed when the refrigerant is reliably accumulated in the storage location (41), the refrigerant can be efficiently discharged.

    Moreover, according to 5th invention, in the storage operation | movement which stopped the driving | operation of the internal fan (26), until refrigerant | coolant with larger specific gravity than the air which leaked in the warehouse falls and reaches | attains a storage location (41) This time can be easily assumed. Therefore, the end point of the storage operation and the start point of the exhaust operation can be accurately determined based on the elapsed time from the start point of the storage operation. Further, the end point of the storage operation and the start point of the exhaust operation can be easily determined from the elapsed time from the start point of the storage operation.

FIG. 1 is a piping diagram illustrating a configuration of a refrigerant circuit of the refrigeration system according to the first embodiment. FIG. 2 is a side cross-sectional view illustrating a schematic configuration of the refrigeration system according to the first embodiment, and illustrates an operation during a cooling operation. FIG. 3 is a side cross-sectional view illustrating a schematic configuration of the refrigeration system according to the first embodiment, and illustrates a storage operation during an exhaust operation. FIG. 4 is a side cross-sectional view illustrating a schematic configuration of the refrigeration system according to the first embodiment, and illustrates an exhaust operation during the exhaust operation. FIG. 5 is a side cross-sectional view illustrating a schematic configuration of the refrigeration system according to the second embodiment, and illustrates an operation during the cooling operation. FIG. 6 is a side view of the refrigeration system of Embodiment 2 as viewed from the inside of the warehouse. FIG. 7 is an enlarged view illustrating a drainage structure and an exhaust device of the refrigeration system according to the second embodiment. FIG. 8 is a side cross-sectional view illustrating a schematic configuration of the refrigeration system of the second embodiment, and is a diagram illustrating a storage operation during an exhaust operation. FIG. 9 is a side cross-sectional view illustrating a schematic configuration of the refrigeration system of the second embodiment, and illustrates an exhaust operation during an exhaust operation.

    Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature and is not intended to limit the present invention, its application, or its use.

<< Embodiment 1 of the Invention >>
As shown in FIGS. 1 and 2, the refrigeration system (10) is provided in a storage (1) for freezing and storing food or the like and storing the air in the storage (1). It is to be cooled. In the storage (1), the walls, floor, and ceiling are all heat-insulated to avoid heat exchange between the air inside and outside the room. In the present embodiment, the storage (1) has no openings other than the carry-in / out entrance (2) in order to suppress the entry of outside air. Moreover, it is comprised by the structure with high airtightness which suppressed the penetration | invasion of the external air from the clearance gap between a wall and a floor and a wall and a ceiling.

    The refrigeration system (10) includes an external unit (11), an internal unit (12), an exhaust device (13), a refrigerant sensor (14), and a controller (15).

<External unit / Internal unit>
The outside unit (11) is installed outside the storage (1), and the inside unit (12) is installed inside the storage (1). The external unit (11) and the internal unit (12) are provided with a refrigerant circuit (20) that circulates the refrigerant and performs a vapor compression refrigeration cycle across both units (11, 12). It has been.

<Refrigerant circuit>
As shown in FIG. 1, the refrigerant circuit (20) connects a compressor (21), a condenser (22), an expansion valve (23), and an evaporator (24) in order by refrigerant piping. It is a closed circuit constituted by. In the present embodiment, the refrigerant circuit (20) is filled with a slightly flammable R32 (HFC32) refrigerant having a specific gravity greater than that of air. The compressor (21), the condenser (22), and the expansion valve (23) are accommodated in the external casing (11a) of the external unit (11), and the evaporator (24) is the internal unit. It is accommodated in the internal casing (12a) of (12). The liquid side communication pipe (27) and the gas side communication pipe (28) arranged between the external unit (11) and the internal unit (12) are respectively the interior and the storage of the storage (1). It is provided across the outside.

    An outside fan (25) for sending outside air (outside air) to the condenser (22) in the outside casing (11a) is provided in the vicinity of the condenser (22) in the outside casing (11a). ing. In the condenser (22), heat is generated between the refrigerant pressurized by the compressor (21) and flowing inside the condenser (22) and the outside air sent to the condenser (22) by the external fan (25). Exchange is performed. In the present embodiment, the external fan (25) is a propeller fan.

    In the internal casing (12a), an internal fan (26) that sends internal air to the evaporator (24) in the internal casing (12a) is provided in the vicinity of the evaporator (24). In the evaporator (24), the pressure is reduced by the expansion valve (23) and flows between the refrigerant flowing in the evaporator (24) and the internal air sent to the evaporator (24) by the internal fan (26). Heat exchange takes place. The internal fan (26) is provided so as to suck in the internal air cooled by the refrigerant in the evaporator (24) and blow it out into the internal space so as to circulate in the internal space.

《Drainage structure》
In addition, a drain pan (31) for receiving condensed water generated in the evaporator (24) is provided at the bottom of the internal casing (12a). The drain pan (31) has an inclined surface whose height decreases from both ends in the left-right direction in FIG. 2 toward the center and decreases from the back side to the near side in the paper penetration direction in FIG. doing. In the center of the drain pan (31), a discharge portion (32) for discharging condensed water from the drain pan (31) is formed, and a drain hose (drain pipe) (33) is connected to the discharge portion (32). ing. The drain hose (33) is arranged so as to penetrate the side wall of the storage (1) from the inside to the outside of the storage. A check valve (34) is provided at a portion of the drain hose (33) disposed outside the storage to prevent outside air from entering the storage.

<Exhaust device>
The exhaust device (13) includes a storage container (storage location) (41), an exhaust hose (communication path) (42), an exhaust valve (open / close valve) (43), and an air guide mechanism (44). Yes.

《Storage container》
The storage container (41) is an open container at the top, and is provided in the lower part of the storage for storing a refrigerant having a specific gravity greater than that of air leaking from the refrigerant circuit (20) of the storage unit (12). ing. In the present embodiment, the storage container (41) is provided below the internal unit (12). The reason why it is provided below the internal unit (12) is that most of the refrigerant leaking from the refrigerant circuit (20) into the internal compartment leaks around the evaporator (24), that is, around the internal unit (12). This is to receive the refrigerant that leaks around the unit (12) and falls downward. The storage container (41) has a cylindrical discharge part (45) formed at the center of the bottom surface. Further, the bottom surface of the storage container (41) is configured as a mortar-shaped inclined surface whose height decreases from the outer edge toward the discharge part (45).

《Exhaust hose》
The exhaust hose (42) is connected to the discharge part (45). The exhaust hose (42) is arranged so as to penetrate the side wall of the storage (1) from the inside to the outside of the storage.

    The exhaust valve (43) is connected to a portion of the exhaust hose (42) disposed in the warehouse. The exhaust valve (43) is configured by an open / close solenoid valve, and is switched between an open state in which the inside and outside of the warehouse are communicated and a closed state in which the inside and outside of the warehouse are not communicated.

<Air guide mechanism>
In this embodiment, the air guide mechanism (44) includes a V-shaped air guide plate (46) and a hinge (47). The wind guide plate (46) is formed of a V-shaped folded plate member, and hinges (47) are provided at corners of the wind guide plate (46). The wind guide mechanism (44) is provided so that the hinge (47) extends in a direction substantially perpendicular to the blowing direction of the internal fan (26) on the blow side and below the internal fan (26). Yes.

    In addition, the wind guide mechanism (44) rotates the wind guide plate (46) around the hinge (47), so that the first state (see the solid line in FIG. 2 and the two-dot chain line in FIG. 4) and the second state ( 2) (refer to the two-dot chain line in FIG. 2 and the solid line in FIG. 4). In the first state, the V-shaped air guide plate (46) is opened upward so that the air blown from the internal fan (26) is guided in the internal circulation direction by the air guide plate (46). It is a certain state. At this time, the first part (46a) on the side of the internal unit (12) with respect to the hinge (47) of the air guide plate (46) extends toward the internal unit (12), and the second part on the opposite side (46b) extends in the internal circulation direction (horizontal direction). On the other hand, in the second state, the V-shaped air guide plate (46) is connected to the internal unit (46) so that the air blown from the internal fan (26) is guided to the storage container (41) by the air guide plate (46). 12) It is in a position to open toward the point. At this time, the first part (46a) of the air guide plate (46) extends toward the storage container (41), and the second part (46b) on the opposite side is a part of the air blown from the internal fan (26). It extends in the direction (vertical direction) that prevents the flow of the part in the circulation direction in the warehouse.

<Refrigerant sensor>
A refrigerant sensor (14) for detecting refrigerant leaking from the refrigerant circuit (20) of the internal unit (12) is provided in the storage (1). In the present embodiment, the refrigerant sensor (14) is provided in the storage container (41). In the present embodiment, the refrigerant sensor (14) is a metal oxide semiconductor gas sensor. In the refrigerant sensor (14), oxygen ions adsorbed on the surface of the metal oxide semiconductor react with the refrigerant gas and are released from the surface, so that the free electrons inside the sensor increase and the resistance value decreases. By doing so, the gas concentration is obtained. The gas concentration measured by the refrigerant sensor (14) is transmitted to the controller (15).

<controller>
The controller (15) is provided in the outside casing (11a). The controller (15) controls the operation of the compressor (21), the expansion valve (23), the external fan (25), and the internal fan (26) to cool the internal air to a predetermined set temperature. It is comprised so that driving | running | working may be performed. Further, when a refrigerant leak from the refrigerant circuit (20) to the inside of the warehouse is detected from the gas concentration transmitted from the refrigerant sensor (14), an exhaust operation for discharging the leaked refrigerant to the outside of the warehouse is executed. ing. Details of the exhaust operation will be described later.

    In the present embodiment, the controller (15) includes a microcomputer that controls each element of the refrigeration system (10) as disclosed in the present application, and a memory, a hard disk, and the like in which an executable control program is stored. . The controller (15) is an example of a control unit of the refrigeration system (10), and the detailed structure and algorithm of the controller (15) include any hardware and software that execute the functions according to the present invention. A combination of these may be used.

-Driving action-
<Cooling operation>
As shown in FIG. 2, in the refrigeration system (10), the controller (15) performs a cooling operation for cooling the air in the storage (1) to a set temperature. In the cooling operation, the controller (15) controls the operations of the compressor (21), the expansion valve (23), the external fan (25), and the internal fan (26) to compress the vapor in the refrigerant circuit (20). The internal refrigeration cycle is performed, and the air in the storage (1) sent to the evaporator (24) by the internal fan (26) is cooled by the refrigerant passing through the evaporator (24). At this time, the air guide mechanism (44) is controlled to the first state by the controller (15).

    Specifically, in the external unit (11), when the refrigerant compressed in the compressor (21) flows into the condenser (22) and flows through the condenser (22), the external fan (25) Heat exchanges with the outside air sent to the condenser (22), and dissipates heat to the outside air to condense. The condensed liquid refrigerant is depressurized at the expansion valve (23), then flows out of the external unit (11), passes through the liquid side connecting pipe (27), and enters the evaporator (24) of the internal unit (12). Inflow. When the refrigerant flowing into the evaporator (24) flows through the evaporator (24), the refrigerant exchanges heat with the air in the storage (1) sent to the evaporator (24) by the internal fan (26). Then, it absorbs heat from the internal air and evaporates. The evaporated gas refrigerant flows out of the internal unit (12), passes through the gas side connecting pipe (28), is sucked into the compressor (21) of the external unit (11), and is compressed again. On the other hand, the in-compartment air that has been absorbed by the refrigerant and cooled in the evaporator (24) is blown into the interior by the in-compartment fan (26) and circulates in the interior. In this way, the internal air is cooled.

    Further, at this time, the controller (15) causes the compressor (21), the expansion valve, and the like so that the temperature of the air in the storage (1) becomes a desired target temperature based on the measurement result of a temperature sensor (not shown). (23) The operation of the outside fan (25) and the inside fan (26) is controlled.

<Exhaust operation>
In the refrigeration system (10), when the controller (15) detects a refrigerant leak from the refrigerant circuit (20) into the warehouse, an exhaust operation for discharging the leaked refrigerant to the outside is executed. The controller (15) detects refrigerant leakage from the refrigerant circuit (20) to the interior from the gas concentration transmitted from the refrigerant sensor (14). Specifically, when the gas concentration transmitted from the refrigerant sensor (14) exceeds a predetermined first concentration, the controller (15) determines that the refrigerant is in a “refrigerant leak” state, and executes the exhaust operation. In the exhaust operation, the controller (15) controls the operation of the internal fan (26), exhaust valve (43), and air guide mechanism (44) to store the refrigerant leaking into the storage container (41). The storage operation to perform and the exhaust operation to discharge the stored refrigerant to the outside of the warehouse.

《Storage operation》
As shown in FIG. 3, in the storage operation, the controller (15) stops the operation of the internal fan (26), maintains the closed exhaust valve (43) as it is, and closes the first state. The air guide mechanism (44) is maintained in the first state as it is. When the operation of the internal fan (26) is stopped, the stopped state is maintained. When the operation of the internal fan (26) is stopped, the internal air no longer circulates in the internal storage, so that the refrigerant having a specific gravity greater than that of the air falls without being diffused by the internal fan (26). Due to the storage operation in which the operation of the internal fan (26) is stopped, the leaked refrigerant is stored in the storage container (41) provided at the refrigerant drop point.

    When a certain amount of refrigerant is stored in the storage container (41), the controller (15) ends the storage operation and performs the exhaust operation. Specifically, when the gas concentration transmitted from the refrigerant sensor (14) exceeds a predetermined second concentration higher than the first concentration, the controller (15) has a certain amount of refrigerant in the storage container (41). Is stored, and the storage operation is terminated.

<Exhaust operation>
As shown in FIG. 4, in the exhaust operation, the controller (15) restarts the operation of the internal fan (26) and switches the closed exhaust valve (43) to the open state. Further, the controller (15) switches the air guide mechanism (44) in the first state to the second state. By resuming the operation of the internal fan (26), the internal air circulates in the internal space. On the other hand, the air blowing mechanism (44) in the second state causes a part of the lower part of the air blown from the internal fan (26) Guided to storage container (41). Specifically, a part of the blown air hits the second portion (46b) extending in the vertical direction of the V-shaped air guide plate (46), and the lower first portion along the second portion (46b). (46a) is led to the storage container (41) by the first portion (46a) of the air guide plate (46) that flows toward the storage container (41). In this way, a part of the air blown from the internal fan (26) is blown into the storage container (41), whereby the refrigerant stored in the storage container (41) by the storage operation becomes the storage container (41). It is pushed into the discharge part (45) formed at the lowest position of the bottom plate of the plate. As described above, in the exhaust operation, since the exhaust valve (43) is switched to the open state, the inside and outside of the storage are in communication with each other by the exhaust hose (42). Therefore, the refrigerant pushed into the discharge part (45) by the blown air is discharged to the outside through the exhaust hose (42) together with the inside air. The operation of the internal fan (26) is restarted, the exhaust valve (43) is opened, and the air is introduced into the storage container (41) by the air guide mechanism (44). By the operation, the refrigerant stored in the storage container (41) passes through the exhaust hose (42) and is discharged to the outside.

    The controller (15) ends the exhaust operation when the refrigerant stored in the storage container (41) is discharged to some extent. Specifically, the controller (15) stores the gas in the storage container (41) when the gas concentration transmitted from the refrigerant sensor (14) is lower than the first concentration used as a reference for starting the exhaust operation. The exhausting operation is terminated assuming that the refrigerant has been discharged to some extent.

-Effect of Embodiment 1-
According to the first embodiment, when the refrigerant in the refrigerant circuit (20) leaks into the warehouse, the exhaust fan that exhausts the refrigerant to the outside of the warehouse is not immediately performed, but the internal fan (26) is operated. The refrigerant that stopped and leaked was determined to be stored after the storage operation of storing the refrigerant in the storage container (41) below. Thereby, when a refrigerant | coolant leaks in a store | warehouse | chamber, the leaked coolant can be collectively discharged | emitted in the state stored in the storage location (41) to some extent. Therefore, compared with the case where the exhaust operation is performed immediately when the refrigerant leaks into the warehouse, the refrigerant leaking into the warehouse can be efficiently discharged outside the warehouse without exhausting the air in the warehouse. . Accordingly, it is possible to suppress an increase in the temperature of the air in the storage accompanying the discharge of the refrigerant leaking into the storage.

    Further, according to the first embodiment, the wind guide mechanism (44) for switching the flow direction of the blown air of the internal fan (26) is provided, and when performing the cooling operation, the wind guide mechanism (44) is the first. In the evaporator, the internal air cooled by the refrigerant in the evaporator (24) is circulated in the internal compartment, and when the exhaust operation is performed, the air guide mechanism (44) is switched to the second state and the storage container ( It was decided that the refrigerant stored in 41) would be discharged to the outside using the dynamic pressure of the air blown from the internal fan (26). As a result, during the cooling operation, the refrigerant stored in the storage container (41) is used during the exhaust operation without disturbing the air circulation in the warehouse, and the dynamic pressure of the air blown from the internal fan (26) is used. And can be smoothly discharged to the outside.

    Further, according to the first embodiment, the end point of the storage operation and the start point of the exhaust operation are determined based on the refrigerant concentration in the air in the storage container (41). Therefore, since the exhaust operation can be performed when the refrigerant is reliably accumulated in the storage container (41), the refrigerant can be efficiently discharged.

-Modification of Embodiment 1-
In the said Embodiment 1, in order to discharge | emit the refrigerant | coolant which leaked in the store | warehouse | chamber outside to the store | warehouse | chamber, it was supposed that the exhaust hose (42) was provided ranging over the store | chamber interior and the exterior. However, the exhaust hose (42) may connect the discharge portion (45) of the storage container (41) and the portion of the drain hose (33) disposed in the warehouse. By using a part of the drain hose (33) as an exhaust communication path in this way, a path for discharging the refrigerant can be easily formed without providing a new path connecting the outside and the inside of the warehouse. Can do.

<< Embodiment 2 of the present invention >>
As shown in FIG. 5, the refrigeration system (10) according to the second embodiment is provided in a container (storage) (1) used when storing food by freezing or storing it or transporting it by sea while refrigerated. The inside air of the container (1) is cooled. In the container (1), the walls, floor, and ceiling are all insulated so as to avoid heat exchange between the inside air and the outside air. Further, the container (1) is formed in an elongated box shape with one end face opened, a carry-in / out entrance (2) is formed on the front side (right side in FIG. 5), and the container (1) is frozen on the back side (left side in FIG. 5). A system (10) is provided.

    In the second embodiment, the refrigeration system (10) includes the external unit (11), the internal unit (12), the exhaust device (13), the refrigerant, as in the refrigeration system (10) of the first embodiment. A sensor (14) and a controller (15) are provided, and instead of the external casing (11a) and the internal casing (12a) of Embodiment 1, the external unit (11) and the internal unit (12) The casing (50) which accommodates the component apparatus is provided.

<casing>
As shown in FIG. 5, the casing (50) includes a warehouse outer wall (51) located outside the warehouse of the container (1), and a warehouse inner wall (52) located inside the warehouse of the container (1). . The outer wall (51) and the inner wall (52) are made of, for example, an aluminum alloy.

    The outer wall (51) is attached to the peripheral edge of the opening of the container (1) so as to close the opening end of the container (1). The warehouse outer wall (51) is formed so that the lower part bulges to the inside of the container (1).

    The warehouse inner wall (52) is arrange | positioned facing the warehouse outer wall (51). The inner wall (52) bulges to the inner side corresponding to the lower part of the outer wall (51). A heat insulating material (53) is provided in the space between the internal wall (52) and the external wall (51).

    Thus, the lower part of the casing (50) is formed so as to bulge toward the inner side of the container (1). As a result, an outside storage space (S1) in which the components of the outside unit (11) are stored is formed outside the container (1) in the lower part of the casing (50), and the upper part of the casing (50). An internal storage space (S2) for storing the components of the internal unit (12) is formed inside the container (1).

    A partition plate (55) is disposed in the container (1). The partition plate (55) is configured as a substantially rectangular plate member, and is erected in a posture facing the inner surface of the container (1) of the casing (50). By this partition plate (55), the interior of the container (1) and the interior storage space (S2) are partitioned.

    A suction port (55a) is formed between the upper end of the partition plate (55) and the ceiling surface in the container (1). The internal air of the container (1) is taken into the internal storage space (S2) through the suction port (55a).

    In the container (1), a floor board (56) is provided with a gap between the bottom surface of the container (1). On the floor board (56), a boxed storage is placed. An underfloor channel (56a) is formed between the bottom surface in the container (1) and the floor plate (56). A gap is provided between the lower end of the partition plate (55) and the bottom surface in the container (1), and communicates with the underfloor channel (56a).

    On the front side (right side in FIG. 5) of the container (1) on the floor board (56) is an air outlet (55b) that blows out the air cooled by the container refrigeration system (10) into the container (1). Is formed.

<External unit / Internal unit>
As described above, in Embodiment 2, the external unit (11) is installed in the external storage space (S1) of the container (1), and the internal unit (12) is stored in the internal storage of the container (1). It is installed in the space (S2). The external unit (11) and the internal unit (12) are provided with a refrigerant circuit (20) similar to that of the first embodiment, straddling both units (11, 12). Since the structure of a refrigerant circuit (20) is the same as that of Embodiment 1, description is abbreviate | omitted.

    As shown in FIG. 5, the compressor (21) and the condenser (22) are stored in the external storage space (S1). The condenser (22) is provided in the central portion in the vertical direction of the external storage space (S1). An external fan (25) is provided above the condenser (22), and a compressor (21) is provided below the condenser (22).

    On the other hand, the evaporator (24) is stored in the storage space (S2). An internal fan (26) is provided above the evaporator (24) in the internal storage space (S2).

《Drainage structure》
Moreover, in Embodiment 2, the drain pan (31) which receives the dew condensation water which generate | occur | produces in this evaporator (24) is provided under the evaporator (24) in the storage space (S2). As shown in FIG. 6, the drain pan (31) has inclined surfaces whose height decreases from both ends in the width direction of the casing (50) toward the center. A drain hose (drain pipe) (33) that discharges condensed water from the drain pan (31) is connected to the center of the drain pan (31), and the drain hose (33) is drawn out to the outside storage space (S1). Yes.

    As shown in FIG. 7, a trap (non-return portion) (35) for preventing a backflow of outside air is formed in a portion of the drain hose (33) accommodated in the outside storage space (S1). . The drain hose (33) is connected to a bypass hose (bypass passage) (36) that bypasses the trap (35), and the bypass hose (36) is provided with an exhaust valve (43). .

<Exhaust device>
Also in the second embodiment, the exhaust device (13) includes a storage container (storage location) (41), an exhaust hose (communication path) (42), an exhaust valve (open / close valve) (43), and an air guide mechanism ( 44).

    In Embodiment 2, the storage container (41) is comprised by the drain pan (31). Here, since most of the refrigerant that leaks from the refrigerant circuit (20) into the cabinet leaks around the evaporator (24), the refrigerant is evaporated by the drain pan (31) that is provided below the evaporator (24) and receives the condensed water. The refrigerant leaking around the vessel (24) and falling downward can be received. The exhaust hose (42) is constituted by a drain hose (33) and a bypass hose (36).

    In the second embodiment, the air guide mechanism (44) is constituted by a flat air guide plate (46) and a hinge (47) as shown in FIG. The hinge (47) is provided at the end of the air guide plate (46). The wind guide mechanism (44) is a direction (horizontal direction) in which the hinge (47) is substantially orthogonal to the blowing direction (downward direction) of the internal fan (26) on the lower side and on the lower side of the internal fan (26). ) To extend. The hinge (47) extends in the horizontal direction along the width direction of the drain pan (31).

    In addition, the air guide mechanism (44) is configured so that the air guide plate (46) rotates around the hinge (47) so that the first state (see the solid line in FIG. 5 and the two-dot chain line in FIG. 9) and the second state ( 5 (see the two-dot chain line in FIG. 5 and the solid line in FIG. 9). In the first state, the flat air guide plate (46) is in the same direction as the internal circulation direction so that the air blown from the internal fan (26) is guided in the internal circulation direction by the air guide plate (46), That is, it is a state extending downward from the hinge (47). On the other hand, the second state is a flat air guide plate (46) so that the air blown from the internal fan (26) is guided to the storage container (41) comprising the drain pan (31) by the air guide plate (46). Is a state extending obliquely upward in a direction away from the drain pan (31) from the hinge (47).

<Refrigerant sensor>
A refrigerant sensor (14) for detecting refrigerant leaking from the refrigerant circuit (20) of the internal unit (12) is provided in the storage (1). Also in the second embodiment, the refrigerant sensor (14) is provided in the storage container (41) including the drain pan (31). Also in the second embodiment, the refrigerant sensor (14) is configured by a metal oxide semiconductor gas sensor, and the gas concentration measured by the refrigerant sensor (14) is transmitted to the controller (15).

<controller>
The controller (15) is provided in the external storage space (S1). Also in the second embodiment, the controller (15) controls the operation of the compressor (21), the expansion valve (23), the external fan (25), and the internal fan (26), so that the internal air is predetermined. A cooling operation for cooling to a set temperature is performed. Further, when a refrigerant leak from the refrigerant circuit (20) to the inside of the warehouse is detected from the gas concentration transmitted from the refrigerant sensor (14), an exhaust operation for discharging the leaked refrigerant to the outside of the warehouse is executed. ing. Details of the exhaust operation will be described later.

-Driving action-
<Cooling operation>
In the refrigeration system (10), the controller (15) performs a cooling operation for cooling the internal air of the container (1) to a set temperature. In the cooling operation, the controller (15) controls the operations of the compressor (21), the expansion valve (23), the external fan (25), and the internal fan (26) to compress the vapor in the refrigerant circuit (20). The internal refrigeration cycle is performed, and the internal air of the container (1) sent to the evaporator (24) by the internal fan (26) is cooled by the refrigerant passing through the evaporator (24). The operation of the refrigerant in the refrigerant circuit (20) during the cooling operation is the same as that in the first embodiment. At this time, the air guide mechanism (44) is controlled to the first state by the controller (15). The internal air of the container (1) is sent to the evaporator (24) by the internal fan (26), and is cooled by being absorbed by the refrigerant flowing through the evaporator (24). The cooled interior air is blown into the interior by the interior fan (26) and circulates in the interior. In this way, the internal air is cooled.

    Further, at this time, the controller (15) causes the compressor (21), the expansion valve (to increase the temperature of the air in the container (1) to a desired target temperature based on the measurement result of a temperature sensor (not shown). 23) Control the operation of the external fan (25) and internal fan (26).

<Exhaust operation>
Also in the second embodiment, in the refrigeration system (10), when the controller (15) detects a refrigerant leak from the refrigerant circuit (20) into the cabinet, the exhaust for discharging the leaked refrigerant to the outside of the cabinet. Operation is performed. The controller (15) detects refrigerant leakage from the refrigerant circuit (20) to the interior from the gas concentration transmitted from the refrigerant sensor (14). Specifically, when the gas concentration transmitted from the refrigerant sensor (14) exceeds a predetermined first concentration, the controller (15) determines that the refrigerant is in a “refrigerant leak” state, and executes the exhaust operation. In the exhaust operation, the controller (15) controls the operation of the internal fan (26), exhaust valve (43), and air guide mechanism (44) to store the refrigerant leaking into the storage container (41). The storage operation to perform and the exhaust operation to discharge the stored refrigerant to the outside of the warehouse.

《Storage operation》
As shown in FIG. 8, in the storing operation, the controller (15) stops the operation of the internal fan (26) and maintains the closed exhaust valve (43) as it is. On the other hand, the controller (15) switches the air guide mechanism (44) in the first state to the second state. When the operation of the internal fan (26) is stopped, the stopped state is maintained. When the operation of the internal fan (26) is stopped, the internal air no longer circulates in the internal storage, so that the refrigerant having a specific gravity greater than that of the air falls without being diffused by the internal fan (26). Due to the storage operation in which the operation of the internal fan (26) is stopped, the leaked refrigerant is stored in the storage container (41) including the drain pan (31) provided at the refrigerant drop point.

    When a certain amount of refrigerant is stored in the drain pan (31), the controller (15) ends the storage operation and performs the exhaust operation. Specifically, when the gas concentration transmitted from the refrigerant sensor (14) exceeds a predetermined second concentration higher than the first concentration, the controller (15) causes a certain amount of refrigerant in the drain pan (31). The storage operation is terminated as having been stored.

<Exhaust operation>
As shown in FIG. 9, in the exhaust operation, the controller (15) restarts the operation of the internal fan (26) and switches the closed exhaust valve (43) to the open state. Furthermore, the controller (15) maintains the air guide mechanism (44) in the second state in the second state. By resuming operation of the internal fan (26), the internal air circulates in the internal space, while the air blowing mechanism (44) in the second state causes the air blown from the internal fan (26) to flow from the drain pan (31). To the storage container (41). Specifically, the blown air hits the drain pan (31) and the wind guide plate (46), and is connected to the lowermost part of the drain pan (31) along the drain pan (31) and the wind guide plate (46). Guided to hose (33). In this way, when the blown air of the internal fan (26) is blown into the drain pan (31), the refrigerant stored in the drain pan (31) by the storage operation is connected to the lowermost part of the drain pan (31). Pushed into the drain hose (33). As described above, since the exhaust valve (43) is switched to the open state in the exhaust operation, the inside and outside of the compartment are in communication with each other by the exhaust hose (42) including the drain hose (33). Yes. Therefore, the refrigerant pushed into the drain hose (33) by the blown air is discharged to the outside through the exhaust hose (42) including the drain hose (33) together with the inside air. Such an operation of the internal fan (26) is resumed, the exhaust valve (43) is opened, and the exhaust operation for guiding the blown air to the drain pan (31) by the air guide mechanism (44) causes the storage container to be The refrigerant stored in (41) is exhausted outside through the exhaust hose (42) comprising the drain hose (33).

    The controller (15) ends the exhaust operation when the refrigerant stored in the drain pan (31) is discharged to some extent. Specifically, the controller (15) was stored in the drain pan (31) when the gas concentration transmitted from the refrigerant sensor (14) was lower than the first concentration used as a reference for starting the exhaust operation. The exhaust operation is terminated assuming that the refrigerant has been discharged to some extent.

-Effect of Embodiment 2-
In the second embodiment, the same effect as in the first embodiment can be obtained.

    Further, according to the second embodiment, the existing drain hose (drain pipe) (33) is used as a communication path for discharging the refrigerant leaking into the warehouse to the outside. Specifically, the existing drain hose (33) is provided with a bypass hose (36) that bypasses the trap (check portion) (35), and the bypass hose (36) has an exhaust valve (open / close valve) (43 ). By providing the bypass hose (36) and the exhaust valve (43) in this way and using the existing drain hose (33), the refrigerant can be supplied without providing a new passage that connects the outside and the inside of the warehouse. A discharge path can be easily formed.

<< Other Embodiments >>
About each said embodiment, it is good also as the following structures.

    In each of the above embodiments and modifications, the timing for ending the storage operation and starting the exhaust operation is determined based on the refrigerant concentration in the air in the storage container (41). However, the determination of the timing to end the storage operation and start the exhaust operation is not limited to the examples of the first and second embodiments. For example, a timer that measures the elapsed time from the start of the storage operation is provided, and a sufficient time for the refrigerant that has leaked into the warehouse to fall and reach the storage container (41) is predicted. If the above drop time is exceeded, the storage operation may be terminated and the exhaust operation may be performed. In the storage operation in which the operation of the internal fan (26) is stopped, the time until the refrigerant having a specific gravity that is larger than the air leaking into the internal space falls and reaches the storage container (41) can be easily assumed. . Therefore, as described above, the end point of the storage operation and the start point of the exhaust operation can be accurately determined based on the elapsed time from the start point of the storage operation. Further, the end point of the storage operation and the start point of the exhaust operation can be easily determined from the elapsed time from the start point of the storage operation.

    In each of the above embodiments and modifications, the storage container (41) is provided below the evaporator (24) to store the leaked refrigerant, but the evaporator (24) The area below 24) may be a refrigerant storage location, and the communication path may be opened in the area below the evaporator (24).

    Furthermore, in Embodiment 2 described above, the drain pipe provided on the bottom of the container (2) is used as a storage location according to the present invention, and a drain pipe for discharging condensed water received by the drain pan of the container (2) to the outside of the container is provided. It is good also as a communicating path concerning the present invention. At this time, the refrigerant sensor (14) is preferably provided on the drain pan.

    In the second embodiment, the drain hose (33) is provided with a bypass hose (36) that bypasses the trap (35) that prevents the outside air from flowing into the warehouse in the drain hose (33), and the exhaust hose is operated. Occasionally, the internal air is configured to be discharged outside the bypass, bypassing the trap (35).

    By the way, the non-return structure for preventing the outside air from flowing into the storage in the drain pipe such as the drain hose (33) is limited to the trap (35) made of the U-shaped or S-shaped pipe as described above. Absent. For example, there is a case where an air cut valve having a rubber valve that is normally deformed so as to open a pipe line when drain water flows in, while shielding the pipe line of the drain pipe, may be used as the check structure. In such a case, a bypass hose (36) and an exhaust valve (43) are provided to bypass the air cut valve as a check portion that prevents the outside air from flowing into the drain pipe. What is necessary is just to comprise so that the air in a store | warehouse | chamber may be discharged | emitted outside a storehouse bypassing an air cut valve. Even in such a case, as in the second embodiment, by providing the bypass hose (36) and the exhaust valve (43) and using the existing drain hose (33), the outside and inside of the chamber are stored. A path for discharging the refrigerant can be easily formed without providing a new passage connecting the two.

    As described above, the present invention is useful for a refrigeration system for cooling the air inside the storage.

1 storage
10 Refrigeration system
20 Refrigerant circuit
24 Evaporator
26 Fan inside
27 Liquid side communication piping
28 Gas side communication piping
33 Drain hose (drain piping)
35 Trap (check part)
36 Bypass hose (bypass passage)
41 Storage container (storage location)
42 Exhaust hose (communication path)
43 Exhaust valve (open / close valve)
44 Air guide mechanism

Claims (5)

In the storage (1),
A refrigerant circuit (20) in which the refrigerant circulates and performs a refrigeration cycle;
In the storage of the storage (1), the air in the storage (1) passes through the evaporator (24) connected to the refrigerant circuit (20) and exchanges heat with the refrigerant. With an internal fan (26) that circulates air,
A refrigeration system for a storage that performs a cooling operation for cooling the air in the storage (1),
A communication path (42) connecting the inside and outside of the storage,
An on-off valve (43) provided in the communication path (42),
The refrigerant of the refrigerant circuit (20) is a refrigerant having a larger specific gravity than air,
When the refrigerant in the refrigerant circuit (20) leaked into the warehouse, the operation of the internal fan (26) was stopped and the leaked refrigerant was provided below the evaporator (24) in the warehouse. A storage operation for storing in a predetermined storage location (41) is performed. After the storage operation is completed, the on-off valve (43) is opened and the operation of the internal fan (26) is resumed to return to the storage location (41). A refrigeration system for storage, wherein the storage refrigerant is configured to perform an exhaust operation for discharging the stored refrigerant out of the storage. In claim 1,
A first state for guiding the blown air of the internal fan (26) in the direction of circulation in the internal compartment, and the internal fan (26 so that the refrigerant stored in the storage location (41) is discharged outside the internal compartment. A wind guide mechanism (44) configured to switch to a second state in which at least a part of the blown air of
The refrigeration for a storage case is characterized in that the air guide mechanism (44) is switched to the first state when the cooling operation is performed, and is switched to the second state when the exhaust operation is performed. system. In claim 1 or 2,
The communication path (42)
It has a non-return part (35) that is installed across the inside and outside of the compartment and prevents outside air from flowing into the compartment, and discharges the condensed water generated in the evaporator (24) to the outside. Drain piping (33),
A bypass passage (36) provided in the drain pipe (33) so as to bypass the check portion (35),
The storage refrigeration system, wherein the on-off valve (43) is provided in the bypass passage (36). In any one of Claims 1 thru | or 3,
The storage refrigeration system is configured to terminate the storage operation and perform the exhaust operation when the refrigerant concentration in the air at the storage location (41) exceeds a predetermined upper limit concentration. . In any one of Claims 1 thru | or 3,
A storage refrigeration system configured to end the storage operation and perform the exhaust operation when a predetermined time has elapsed from the start of the storage operation.

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