JP7199249B2 - Showcase - Google Patents

Description

The present invention relates to showcases.

In a refrigerated showcase using a flammable refrigerant, by providing a plurality of communication holes and legs in the bottom plate of the machine room, in case of refrigerant leakage, exhaust can be discharged not only from the side of the machine room but also from the bottom. is known (see, for example, Patent Document 1).

JP 2012-107823 A

However, in the showcase as disclosed in Patent Document 1, when the refrigerant leaks into the machine room from the cooling condenser, the refrigerant piping, etc., the leaked refrigerant flows out of the showcase. If the refrigerant is heavier than air, the leaked refrigerant may accumulate on the floor surface of the indoor space where the showcase is installed, creating a region where the refrigerant concentration exceeds a certain level in the indoor space. There is

The present invention has been made to solve such problems. The purpose is to provide a showcase that can suppress the formation of a region where the concentration of the refrigerant exceeds a certain level in the indoor space where the showcase is installed when the refrigerant leaks from the condenser or the like into the machine room. be.

A showcase according to the present invention includes a housing in which a storage room and a machine room are formed, and a condenser that is housed in the machine room and in which a refrigerant heavier than air flows. The machine room has an air supply port for introducing outside air into the machine room and an exhaust port for discharging the air that has passed through the condenser to the outside of the machine room. at least a portion of the vent is exposed to the indoor space, and leakage detecting means for detecting leakage of the refrigerant in the machine room; and closing means for closing at least the air vent exposed to the indoor space when leakage of the refrigerant in the room is detected.

According to the showcase according to the present invention, when the refrigerant leaks from the condenser or the like into the machine room, it is possible to suppress the formation of a region where the refrigerant concentration exceeds a certain level in the indoor space where the showcase is installed. Effective.

1 is a perspective view of a showcase according to Embodiment 1 of the present invention; FIG. 1 is a refrigerant circuit diagram of a refrigerating cycle provided in a showcase according to Embodiment 1 of the present invention; FIG. 1 is a top perspective view of the inside of a machine room of a showcase according to Embodiment 1 of the present invention; FIG. FIG. 2 is a perspective view schematically showing a main part of the machine room of the showcase according to Embodiment 1 of the present invention; 1 is a perspective view schematically showing the configuration of a closing device provided in a showcase according to Embodiment 1 of the present invention; FIG. 1 is a block diagram showing the configuration of a showcase control system according to Embodiment 1 of the present invention; FIG. FIG. 4 is a flow diagram showing an example of the operation of the showcase according to Embodiment 1 of the present invention; FIG. 10 is a diagram illustrating the configuration of a closing device included in the showcase according to Embodiment 2 of the present invention; FIG. 11 is a cross-sectional view showing a state in which the showcase closing device according to Embodiment 3 of the present invention is not in operation. FIG. 11 is a cross-sectional view showing a state when the showcase closing device according to Embodiment 3 of the present invention is in operation; FIG. 4 is a rear view of a showcase according to Embodiment 3 of the present invention;

Embodiments for carrying out the present invention will be described with reference to the accompanying drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and overlapping descriptions are appropriately simplified or omitted. The present invention is not limited to the following embodiments, and can be modified in various ways without departing from the scope of the present invention.

Embodiment 1.
Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 7. FIG. FIG. 1 is a perspective view of a showcase. FIG. 2 is a refrigerant circuit diagram of a refrigeration cycle provided in the showcase. FIG. 3 is a top perspective view of the interior of the showcase machine room. FIG. 4 is a perspective view schematically showing the main part of the machine room of the showcase. FIG. 5 is a perspective view schematically showing the configuration of a closing device provided in the showcase. FIG. 6 is a block diagram showing the configuration of the showcase control system. And FIG. 7 is a flow chart showing an example of the operation of the showcase.

A showcase 100 according to this embodiment is a closed (reach-in) showcase installed in a supermarket, a convenience store, or the like to store and display beverages, foods, and the like. The showcase 100 may be an open showcase that does not have a door for opening and closing the storage compartment.

As shown in FIG. 1, the showcase 100 includes a housing 10. As shown in FIG. The housing 10 has a rectangular parallelepiped box shape as a whole. A storage room 11 and a machine room 14 are formed in the housing 10 . The storage room 11 is a space in which beverages, perishables, etc. to be cooled can be stored. A plurality of display shelves 12 for displaying perishable foods and the like are arranged in the vertical direction and attached to the storage room 11 . The storage chamber 11 is arranged on the upper side of the housing 10 . A machine room 14 is provided on the lower side of the housing 10 .

In the configuration example described here, the showcase 100 is provided with the door 13 . The door 13 opens and closes the front side of the storage room 11 . The door 13 is a glass door, and even when the door 13 is closed, the inside of the storage room 11 can be visually recognized from the outside of the door 13. - 特許庁In this configuration example, the door 13 is of a sliding door type that can move in a preset opening/closing direction. The opening/closing direction of the door 13 is the horizontal direction toward the front surface of the storage chamber 11 .

The showcase 100 has a refrigerant circuit shown in FIG. As shown in the figure, the refrigerant circuit comprises a compressor 3, a condenser 2, an expansion valve 4, and an evaporator 1, which are cyclically connected by refrigerant pipes 7 in this order. Refrigerant is enclosed in the refrigerant circuit including the refrigerant pipe 7 and the like.

From the standpoint of protecting the global environment, it is desirable to use a refrigerant with a low global warming potential (GWP) as the refrigerant to be sealed in the refrigerant circuit. Moreover, the refrigerant sealed in the refrigerant circuit is combustible. This refrigerant has a higher average molecular weight than air. That is, refrigerants are denser than air and heavier than air at atmospheric pressure. Therefore, the refrigerant has the property of sinking downward in the direction of gravity in the air.

Specific examples of such refrigerants include tetrafluoropropene (CF3CF=CH2:HFO-1234yf), difluoromethane (CH2F2:R32), propane (R290), propylene (R1270), ethane (R170), butane (R600 ), isobutane (R600a), 1.1.1.2-tetrafluoroethane (C2H2F4: R134a), pentafluoroethane (C2HF5: R125), 1.3.3.3-tetrafluoro-1-propene (CF3- CH=CHF:HFO-1234ze), carbon dioxide (CO2:R744), etc. (mixed refrigerant) consisting of one or more refrigerants can be used.

The compressor 3 compresses the refrigerant to increase the pressure and temperature of the refrigerant. Compressed refrigerant is discharged from the compressor 3 . A rotary compressor, a scroll compressor, a reciprocating compressor, etc. can be used for the compressor 3, for example.

The condenser 2 exchanges heat between the refrigerant discharged from the compressor 3 and the surrounding air, radiates heat from the refrigerant, and condenses the refrigerant. The condenser fan 6 sends out the air heated by the condenser 2 and sends fresh air around the condenser 2 to promote heat exchange in the condenser 2 .

The expansion valve 4 expands the refrigerant condensed in the condenser 2 and reduces the pressure of the refrigerant. The expansion valve 4 is, for example, a linear electronic expansion valve (LEV) or a capillary tube. A capillary tube is a thin copper tube with an inner diameter of about 0.6 to 2 mm. By using a capillary tube for throttle expansion, it is possible to lower the pressure and temperature of the refrigerant at a lower cost than the LEV.

The evaporator 1 exchanges heat between the refrigerant depressurized by the expansion valve 4 and the ambient air, causing the refrigerant to absorb heat and evaporate. At this time, the air that has exchanged heat with the refrigerant is cooled. That is, the evaporator 1 works as a cooler. The evaporator fan 5 sends out air cooled by the evaporator 1 as a cooler, and also sends fresh air around the evaporator 1 to promote heat exchange in the evaporator 1 .

A vapor compression refrigeration cycle is realized by circulating the refrigerant in the refrigerant circuit configured as described above. A refrigerating cycle realized by this refrigerant circuit functions as a heat pump that transfers heat between the evaporator 1 side and the condenser 2 side. The evaporator fan 5 and the condenser fan 6 are, for example, propeller fans, line flow fans, sirocco fans, and the like.

A discharge port and a suction port (not shown) are formed in the storage chamber 11 . Further, the housing 10 is provided with an air passage (not shown) extending from the inlet to the outlet. This air passage is a ventilation passage separated from the storage room 11 . An evaporator 1 and an evaporator fan 5 are provided in this air passage. When the evaporator fan 5 is driven, cool air generated by passing through the evaporator 1 is blown into the storage chamber 11 through the outlet. A part of the air in the storage chamber 11 is sucked through the suction port. The air sucked through the suction port is cooled by the evaporator 1 and is blown out again into the storage chamber 11 through the blowout port.

As shown in FIG. 3 , the machine room 14 accommodates the condenser 2 , the compressor 3 and the condenser fan 6 . The expansion valve 4 is also accommodated in the machine chamber 14, although not shown in the figure. That is, the showcase 100 is a so-called built-in showcase that incorporates a condensing unit.

As shown in FIGS. 1 and 3, a front panel 15 is provided on the front side of the machine room 14 . An air supply port 17 is formed in the front panel 15 . As shown in FIG. 3 , a rear panel 16 is provided on the rear side of the machine room 14 . An exhaust port 18 is formed in the rear panel 16 . A machine room air passage 19 is formed in the machine room 14 . The machine room air passage 19 is an air passage leading from the air supply port 17 to the exhaust port 18 .

The condenser 2 and the condenser fan 6 are arranged in the machine room air passage 19 . Since the condenser 2 is arranged inside the machine room air passage 19 , the refrigerant pipe 7 connected to the condenser 2 is also arranged inside the machine room air passage 19 . That is, at least part of the refrigerant pipe 7 and the condenser 2 are housed inside the machine room 14 of the housing 10 . Refrigerant heavier than air flows inside the condenser 2 .

The air supply port 17 is an opening for introducing outside air into the machine room 14 . The exhaust port 18 is an opening for discharging air that has passed through the condenser 2 to the outside of the machine room 14 . A vent is formed in the machine room 14 . The air vents of the machine room 14 include the air supply port 17 and the air exhaust port 18 described above.

The showcase 100 is arranged so that at least a part of it is exposed to the indoor space so that a user in the room can take in and out items such as products in the storage room 11 . That is, at least part of the housing 10 is installed to be exposed to the indoor space. Here, the front surface with the door 13 of the storeroom 11 is exposed to the interior space. Therefore, the front panel 15 of the machine room 14 is also exposed to the room space. At least a part of the ventilation port described above is exposed to the indoor space. That is, in the configuration example of this embodiment, the air supply port 17 on the front panel 15 of the ventilation ports of the machine room 14 is exposed to the interior space.

The showcase 100 of this embodiment has a closing device 30 . The blocking device 30 is blocking means capable of blocking at least the above-described vent exposed to the indoor space. In the configuration example described here, as shown in FIG. 4, both the air supply port 17 and the air exhaust port 18, which are vents, are provided with blocking devices 30, respectively. However, since the vent exposed to the indoor space is the air supply port 17 here, it is sufficient that at least the air supply port 17 is provided with the blocking device 30 .

Next, the configuration of the closure device 30 of this embodiment will be described with reference to FIG. In the figure, a closing device 30 provided in the air supply port 17 is shown as an example. A blocking device 30 provided at the exhaust port 18 has basically the same configuration. The closing device 30 includes a shutter curtain 31 and a winding section 32 .

The shutter curtain 31 opens and closes the air supply port 17, which is a vent. The shutter curtain 31 is formed by, for example, connecting a plurality of elongated slats. The material of the slats of the shutter curtain 31 is preferably metal such as aluminum or iron. Also, the slats may be plated for rust prevention.

The winding part 32 is provided at the upper edge of the air supply port 17 . The winding unit 32 can wind up the shutter curtain 31 . By winding up the shutter curtain 31 with the winding part 32, the air supply port 17 is opened. Then, the air supply port 17 is closed by letting out the shutter curtain 31 downward from the take-up portion 32 .

In the configuration example shown in FIG. 5 , a groove portion 33 is formed directly below the shutter curtain 31 on the bottom surface of the machine room 14 . When the shutter curtain 31 is lowered, the lower end of the shutter curtain 31 is accommodated inside the groove 33. - 特許庁By doing so, the air supply port 17 can be closed more reliably when the shutter curtain 31 is lowered. A sealing material such as rubber or resin may be provided in the groove 33 to reduce the gap with the shutter curtain 31 .

The showcase 100 of this embodiment includes a coolant leakage sensor 20, as shown in FIG. The refrigerant leak sensor 20 is installed inside the machine room 14 . The refrigerant leakage sensor 20 can detect at least the concentration of the same kind of refrigerant as that enclosed in the refrigerant circuit. For the coolant leakage sensor 20, for example, a contact combustion type, a semiconductor type, a heat conduction type, a low potential electrolysis type, an infrared type, or the like can be used.

An oxygen sensor can also be used as the coolant leak sensor 20 . When an oxygen sensor is used, the oxygen concentration is obtained based on the sensor output, and the concentration of the inflow gas is calculated backward assuming that the decrease in oxygen concentration is due to the inflow gas. can be effectively detected. As the oxygen sensor, for example, a galvanic cell type, a polaro type, a zirconia type, and the like can be used.

In the configuration example shown here, the coolant leakage sensor 20 is arranged below the exhaust port 18 inside the machine room 14 . The exhaust port 18 is the most downstream part of the machine room air passage 19 . Therefore, in this configuration example, the refrigerant leakage sensor 20 is arranged downstream of the condenser 2 in the machine room air passage 19 .

Here, let us consider a case where the refrigerant leaks from any of the components that make up the refrigerant circuit accommodated in the machine room 14, such as the condenser 2, the compressor 3, the refrigerant pipe 7, and the like. When the condenser fan 6 is in operation when a refrigerant leak occurs, the leaked refrigerant flows along the machine room air passage 19 toward the exhaust port 18 and reaches the refrigerant leakage sensor located at the most downstream side of the machine room air passage 19. 20. On the other hand, if the condenser fan 6 is stopped when the refrigerant leakage occurs, no airflow is generated in the machine room 14 . Therefore, the refrigerant that is heavier than air under atmospheric pressure stays in the lower part of the machine room 14 in the direction of gravity and is detected by the refrigerant leak sensor 20 installed in the lower part of the machine room 14 .

As shown in FIG. 3, the machine room 14 houses a control device 50 . The control device 50 is for controlling the overall operation of the showcase 100 . FIG. 6 shows the configuration of the control system of showcase 100 in this embodiment. As shown in the figure, the showcase 100 includes a leakage detection section 51, a storage section 52, a notification section 53 and a control section . Each of these units is configured by a circuit mounted on the control device 50, for example.

The leakage detector 51 detects refrigerant leakage in the machine room 14 based on the detection result of the refrigerant leakage sensor 20 . As described above, the refrigerant leakage sensor 20 can directly or indirectly detect the concentration of refrigerant enclosed in the refrigerant circuit. The coolant leakage sensor 20 outputs a detection signal corresponding to the detected concentration of the coolant.

A detection signal output from the refrigerant leak sensor 20 is input to the leak detector 51 . The leakage detection unit 51 first determines whether or not the refrigerant concentration indicated by the detection signal from the refrigerant leakage sensor 20 is greater than or equal to the first reference concentration. The value of the first reference density is set in advance. The preset first reference density is stored in the storage unit 52 . The leakage detection unit 51 compares the first reference concentration acquired from the storage unit 52 and the refrigerant concentration indicated by the detection signal from the refrigerant leakage sensor 20 to make determination.

When the refrigerant concentration indicated by the detection signal from the refrigerant leakage sensor 20 is equal to or higher than the first reference concentration, the leakage detection unit 51 outputs a refrigerant leakage detection signal to the control unit 54 . The refrigerant leakage detection signal is a signal indicating detection of refrigerant leakage in the machine room 14 . In this manner, the refrigerant leakage sensor 20 and the leakage detection unit 51 constitute leakage detection means for detecting refrigerant leakage in the machine room 14 .

The control unit 54 controls the overall operation of the showcase 100 by controlling actuators included in the showcase 100 . Objects controlled by the control unit 54 include, for example, the evaporator fan 5 and the like, in addition to the condenser fan 6, the compressor 3, and the blocking device 30, which are explicitly shown in FIG.

The control unit 54 operates the closing device 30 when the refrigerant leakage detection signal is input from the leakage detection unit 51 . When the blocking device 30 is activated, the shutter curtain 31 is lowered by the wind-up portion 32 to block the air supply port 17 and the exhaust port 18 which are ventilation ports of the machine room 14 . That is, when the refrigerant leakage sensor 20 and the leakage detection unit 51, which are leakage detecting means, detect refrigerant leakage in the machine room 14, the blocking device 30, which is the blocking means, is a vent hole exposed to at least the indoor space. The air supply port 17 is closed.

Therefore, when the refrigerant leaks into the machine room 14 from the evaporator 1 or the like, it is possible to suppress the leaked refrigerant from flowing out into the indoor space. Therefore, even if the refrigerant rapidly leaks from the condenser 2 or the like into the machine room 14, a rapid increase in refrigerant concentration in the indoor space outside the showcase 100 is prevented. It is possible to suppress the formation of a region in which the concentration exceeds a certain level in a short period of time.

Note that when the refrigerant leakage detection signal is output from the leakage detection unit 51, the notification unit 53 notifies the surrounding users, workers, or the like that the refrigerant has leaked. The notification unit 53 includes a speaker for audibly notifying that refrigerant leakage in the machine room 14 of the showcase 100 has been detected, an LED for notifying with light, or the like. The notification unit 53 is provided, for example, in the housing 10 of the showcase 100 or the like.

The showcase 100 of this embodiment has a power cutoff device 55 . The power cutoff device 55 is power cutoff means capable of cutting off power supply to the showcase 100 . The leakage detection unit 51 determines whether or not the refrigerant concentration indicated by the detection signal from the refrigerant leakage sensor 20 is equal to or higher than the second reference concentration. The value of the second reference density is set in advance to a value greater than the above-described first reference density. The preset second reference density is stored in the storage unit 52 . The leakage detection unit 51 compares the second reference concentration acquired from the storage unit 52 and the refrigerant concentration indicated by the detection signal from the refrigerant leakage sensor 20 to make determination.

When the refrigerant concentration indicated by the detection signal from the refrigerant leakage sensor 20 is equal to or higher than the second reference concentration, the leakage detection unit 51 outputs a refrigerant leakage continuation detection signal to the control unit 54 . The refrigerant leakage continuation detection signal is a signal indicating that it has been detected that the refrigerant leakage in the machine room 14 continues.

The control unit 54 operates the power cutoff device 55 when the refrigerant leakage continuation detection signal is input from the leakage detection unit 51 . When the power cutoff device 55 operates, the power supply to the showcase 100 is cut off. When the coolant leakage sensor 20 detects that the refrigerant concentration in the machine room 14 is equal to or higher than the above-described second reference concentration, the power cutoff device 55 as the power cutoff means, that is, the closing device 30 as the closing means Then, the power supply to the showcase 100 is cut off.

By doing so, it is possible to prevent sparks or the like from being energized in the electrical components in the machine room 14 under the condition that the atmosphere in the machine room 14 contains a refrigerant of a certain concentration or higher. In addition, by setting the second reference concentration for determining the continuation of refrigerant leakage to be higher than the first reference concentration for determining the occurrence of refrigerant leakage, it is possible to suppress unnecessary power shutdown due to malfunction of the leakage detecting means.

Next, an operation example of the showcase 100 configured as described above will be described with reference to the flowchart of FIG. First, in step S1, the leakage detection unit 51 determines whether or not the refrigerant concentration detected by the refrigerant leakage sensor 20 is equal to or higher than a first reference concentration. If the refrigerant concentration is equal to or higher than the first reference concentration, the process proceeds to step S2.

In step S2, the leakage detector 51 outputs a refrigerant leakage detection signal. Then, a refrigerant leakage detection signal is input to the controller 54 , and the controller 54 operates the closing device 30 . When the blocking device 30 is activated, the shutter curtain 31 is lowered by the wind-up portion 32 to block the air supply port 17 and the exhaust port 18 which are ventilation ports of the machine room 14 . Therefore, the refrigerant that has leaked into the machine room 14 is prevented from flowing out from the ventilation opening of the machine room 14 into the indoor space. After step S2, the process proceeds to step S3.

In step S3, the leakage detection unit 51 determines whether or not the refrigerant concentration detected by the refrigerant leakage sensor 20 is equal to or higher than the second reference concentration. If the refrigerant concentration is equal to or higher than the second reference concentration, the process proceeds to step S4.

In step S4, the leakage detector 51 outputs a refrigerant leakage continuation detection signal. Then, a refrigerant leakage continuation detection signal is input to the control unit 54 , and the control unit 54 operates the power cutoff device 55 . When the power cutoff device 55 operates, the power supply to the showcase 100 is cut off. Therefore, under the condition that the atmosphere in the machine room 14 contains a refrigerant of a certain concentration or more, the state in which the electrical components in the machine room 14 are energized can be eliminated. When the process of step S4 is completed, a series of operations is completed.

On the other hand, if the refrigerant concentration is less than the second reference concentration in step S3, the process returns to step S1. Moreover, when the refrigerant concentration is less than the first reference concentration in step S1, the process proceeds to step S5. In step S5, if the refrigerant leakage detection signal is output from the leakage detection unit 51, the leakage detection unit 51 stops outputting the refrigerant leakage detection signal. Then, the input of the refrigerant leakage detection signal to the controller 54 is stopped, and the controller 54 cancels the operation of the blocking device 30 . Further, when the refrigerant leakage detection signal is not output from the leakage detection unit 51 in step S5, the leakage detection unit 51 maintains a state of not outputting the refrigerant leakage detection signal. In this case, the refrigerant leakage detection signal is not input to the controller 54 . Therefore, the control unit 54 keeps the closure device 30 in an unactuated state. After step S5, the process returns to step S1.

When the refrigerant is flammable, for example, the first reference concentration described above is set to 1/4 of the LFL concentration of the refrigerant (LFL = Lower Flammable Limit), and the second reference concentration described above is the LFL concentration of the refrigerant. should be 1/2.

For example, the operation of the showcase 100 when using R290 as the refrigerant will be described with specific numerical examples. It is assumed that the volume of the machine room 14 is 500 L (=0.5 m^3), the amount of refrigerant charged in the refrigerant circuit is 0.15 kg, and the refrigerant leakage speed from the condenser 2 is 2.5 kg/h. In this case, when 216 seconds have elapsed since the refrigerant started to leak, the entire amount of the refrigerant charged in the refrigerant circuit leaks into the machine chamber 14 . Therefore, assuming that all of the leaked refrigerant remains in the machine room 14, the refrigerant concentration in the machine room 14 after 216 seconds have passed since the start of refrigerant leakage is 0.3 kg/m^3 (=17 vol%). becomes.

When an atmosphere sufficiently thicker than the LFL concentration flows into the indoor space from the ventilation opening of the machine room 14, the refrigerant is heavier than the indoor air and accumulates on the indoor floor surface. Therefore, in the indoor space outside the showcase 100, a region where the refrigerant concentration is higher than the LFL concentration can be formed.

In the showcase 100 of this embodiment, after about 6 seconds have passed since the refrigerant started to leak, the refrigerant concentration in the machine room 14 reaches 1/4 of the LFL concentration, which is the first reference concentration. The refrigerant leakage sensor 20 and the leakage detection unit 51 detect refrigerant leakage in the machine room 14 . Then, the blocking device 30 operates to block the ventilation port of the machine room 14, thereby suppressing the refrigerant in the machine room 14 from flowing out into the indoor space. In addition, when about 12 seconds have passed since the refrigerant started to leak, the refrigerant concentration in the machine room 14 reaches 1/2 of the LFL concentration, which is the second reference concentration, and the refrigerant leakage sensor 20 and the leakage detection unit 51 detects continued refrigerant leakage in the machine room 14 . Then, the power cutoff device 55 operates to cut off the power supply to the showcase 100 . Therefore, when about 24 seconds have passed since the refrigerant started to leak and the concentration of the refrigerant in the machine room 14 reaches the LFL concentration, the power supply to the showcase 100 can already be cut off.

Embodiment 2.
Embodiment 2 of the present invention will be described with reference to FIG. FIG. 8 is a diagram illustrating the configuration of a closing device provided in the showcase.

The closing device of Embodiment 1 described above closes the ventilation opening of the machine room with a shutter. On the other hand, the blocking device of Embodiment 2 described here blocks the ventilation opening of the machine room by rotating a plurality of blocking plates. The showcase according to the second embodiment will be described below, focusing on the differences from the first embodiment. The configuration whose description is omitted is basically the same as that of the first embodiment.

In the showcase 100 according to this embodiment, the closing device 30 is provided at least at the air supply port 17 among the ventilation ports of the machine room 14 . The closing device 30 is closing means for closing and closing the air supply port 17 . The closure device 30 of this embodiment includes a closure plate 34 and a shaft portion 35 . The blocking plate 34 is arranged inside the air supply port 17 which is a vent. In the configuration example shown here, a plurality of blocking plates 34 are provided. However, the number of blocking plates 34 may be one or more.

Each blocking plate 34 is an elongated plate-like member. A material for the closing plate 34 is preferably a metal such as aluminum or iron. In addition, the blocking plate 34 may be plated for rust prevention. The longitudinal direction of each blocking plate 34 is arranged parallel to the opening surface of the air supply port 17, and the longitudinal directions of all the blocking plates 34 are arranged parallel to each other.

Each closing plate 34 is provided with a shaft portion 35 . The shaft portions 35 extend outward along the longitudinal direction from both longitudinal ends of the closing plate 34 . Therefore, the shaft portion 35 is arranged parallel to the opening surface of the air supply port 17 . Each closing plate 34 is rotatable around the shaft portion 35 . The shaft portion 35 is rotated by a motor (not shown) or the like to rotate the blocking plate 34 about a rotation axis parallel to the opening surface of the air supply port 17 .

When the surface of the blockage plate 34 with the largest area is parallel to the opening surface of the air supply port 17, the plurality of blockage plates 34 are arranged without gaps, and the air supply port 17 is closed (FIG. 8B). ). From this state, when each blocking plate 34 is rotated by the shaft portion 35, a gap is generated between the blocking plates 34 and the air supply port 17 is opened (FIG. 8(a)). Thus, the closing device 30 of this embodiment can open and close the air supply port 17, which is the ventilation port of the machine room 14, by rotating the blocking plate 34. FIG.

In the configuration example shown here, the shaft portion 35 is arranged horizontally and parallel to the opening surface of the air supply port 17, but the direction of the shaft portion 35 is not limited to this configuration example. Alternatively, for example, the shaft portion 35 may be arranged vertically and parallel to the opening surface of the air supply port 17 . Further, by adjusting the angle of the blocking plate 34, it is possible to guide the air sucked from the air supply port 17 to the condenser 2 and to prevent dust from entering the machine room 14 from the air supply port 17. good.

Other configurations, such as the coolant leakage sensor 20 and the configuration of the control system, are the same as those of the first embodiment. Therefore, the blocking device 30 is activated when the leakage detection means detects refrigerant leakage in the machine room 14 to block at least the ventilation port of the machine room 14 exposed to the indoor space. Therefore, even in the showcase 100 configured as described above, the same effects as in the first embodiment can be obtained. Furthermore, since the blocking device 30 is arranged inside the ventilation port, the space of the machine room 14 can be reduced.

Embodiment 3.
Embodiment 3 of the present invention will be described with reference to FIGS. 9 to 11. FIG. FIG. 9 is a cross-sectional view showing a state in which the closing device of the showcase is not operated. FIG. 10 is a cross-sectional view showing a state in which the closing device of the showcase is in operation. And FIG. 11 is a rear view of the showcase.

Embodiment 3 described here is the configuration of Embodiment 1 or Embodiment 2 described above, in which the discharge port communicating with the machine room via the discharge path is higher than the ventilation port of the machine room in the housing. It is formed in position. The showcase according to the third embodiment will be described below, focusing on the differences from the first and second embodiments. The configuration whose description is omitted is basically the same as that of the first or second embodiment.

In the showcase 100 according to this embodiment, as shown in FIGS. 9 to 11, the housing 10 is formed with the discharge port 40 and the discharge path 42 . The exhaust port 40 is arranged at a position higher than the air supply port 17 and the exhaust port 18 which are vents of the machine room 14 . In the configuration example shown here, the discharge port 40 is positioned at the upper end of the back surface of the housing 10 . The discharge path 42 is a space leading from the inside of the machine room 14 to the discharge port 40 .

In the configuration example shown here, a closing plate 34 is attached to the rear surface of the housing 10 so as to be vertically movable. The discharge path 42 is arranged along the inner side of the blocking plate 34 . During normal operation, ie, when the leakage detecting means described above does not detect refrigerant leakage in the machine chamber 14, the closing plate 34 is positioned on the upper side as shown in FIGS. 9 and 11(a). In this state, the discharge port 40 is closed by the open portion 41 on the upper end side of the closing plate 34 . At the same time, the exhaust port 18 is opened by the closing portion 36 on the lower end side of the closing plate 34 .

When the leak detecting means detects a refrigerant leak in the machine chamber 14, the closing plate 34 is lowered by a driving device (not shown) to the state shown in FIGS. 10 and 11(b). In this state, the discharge port 40 is opened by the open portion 41 on the upper end side of the closing plate 34 . At the same time, the exhaust port 18 is blocked by the blocking portion 36 on the lower end side of the blocking plate 34 . Therefore, the refrigerant that has leaked into the machine room 14 is discharged outside the showcase 100 from the discharge port 40 through the discharge path 42 .

In this configuration example, the opening portion 41 of the closing plate 34 normally closes the discharge port 40, and opening means for opening the discharge port 40 when the leak detection means detects refrigerant leakage in the machine chamber 14. is. The blocking portion 36 of the blocking plate 34 is blocking means for blocking the ventilation port of the machine room 14 when the above-described leakage detection means detects refrigerant leakage in the machine room 14 . Therefore, in this configuration example, the closing means and the opening means are integrally provided by the closing plate 34 .

Although not shown, the air supply port 17 of the machine room 14 is provided with a closing device similar to that of the first or second embodiment. That is, other configurations such as the refrigerant leakage sensor 20, the configuration of the control system, and the like are the same as those in the first or second embodiment. Therefore, the blocking device is activated when the leakage detection means detects refrigerant leakage in the machine room 14, and blocks at least the ventilation port of the machine room 14 exposed to the indoor space.

Therefore, the showcase 100 configured as described above can also achieve the same effects as those of the first or second embodiment. Furthermore, by discharging the leaked refrigerant in the machine room 14 from the discharge port 40, it is possible to suppress an increase in the internal pressure of the machine room 14 when the refrigerant leaks in the machine room 14. FIG. At this time, by discharging the leaked refrigerant in the machine room 14 from the discharge port 40 positioned higher than the vent of the machine room 14, the refrigerant heavier than air stays near the floor surface outside the showcase 100. can be suppressed and diffusion of the refrigerant can be achieved.

In addition, in this embodiment, the above-described opening means may not be provided. That is, the discharge port 40 may always be open regardless of whether or not refrigerant leakage in the machine room 14 is detected.

1 Evaporator 2 Condenser 3 Compressor 4 Expansion Valve 5 Evaporator Fan 6 Condenser Fan 7 Refrigerant Piping 10 Housing 11 Storage Room 12 Display Shelf 13 Door 14 Machine Room 15 Front Panel 16 Rear Panel 17 Air Supply Port 18 Exhaust Port 19 Machine Room Air Path 20 Refrigerant Leakage Sensor 30 Closing Device 31 Shutter Curtain 32 Winding Part 33 Groove 34 Closing Plate 35 Shaft 36 Closing Part 40 Discharge Port 41 Opening Part 42 Discharge Path 50 Control Device 51 Leak Detection Section 52 Storage Section 53 Reporting unit 54 Control unit 55 Power cutoff device 100 Showcase

Claims (8)

a housing in which a storage room and a machine room are formed;
a condenser housed in the machine room and through which a refrigerant heavier than air flows;
At least a portion of the housing is installed to be exposed to the indoor space,
The machine room is formed with a vent including an air supply port for introducing outside air into the machine room and an exhaust port for discharging the air that has passed through the condenser to the outside of the machine room,
At least part of the vent is exposed to the indoor space,
leakage detection means for detecting leakage of the refrigerant in the machine room;
a closing means for closing at least the vent exposed to the indoor space when the leakage detection means detects leakage of the refrigerant in the machine room. The closing means is
a shutter curtain for closing and closing the vent;
The showcase according to claim 1, further comprising a winding section capable of winding up the shutter curtain. The closing means is
a blocking plate disposed inside the vent;
2. The showcase according to claim 1, further comprising a shaft portion that rotates the closure plate about a rotation shaft parallel to the opening surface of the vent. 2. The showcase according to claim 1, wherein the housing is formed with an exhaust port at a position higher than the ventilation port, and an exhaust path leading from the machine room to the exhaust port is formed. 5. The showcase according to claim 4, further comprising opening means for closing said discharge port in a normal state and opening said discharge port when said leakage detecting means detects leakage of said refrigerant in said machine room. 6. The showcase according to claim 5, wherein said closing means and said opening means are integrally provided. The leakage detection means includes a sensor capable of detecting the concentration of the refrigerant in the machine room, and the sensor detects that the concentration of the refrigerant in the machine room is equal to or higher than a preset first reference concentration. when the leakage of the refrigerant in the machine room is detected,
Power supply to the showcase is cut off when the sensor detects that the concentration of the refrigerant in the machine room is equal to or higher than a second reference concentration preset to a value higher than the first reference concentration. 7. The showcase according to any one of claims 1 to 6, further comprising a power cut-off means. 8. The apparatus according to any one of claims 1 to 7, further comprising notifying means for notifying that leakage of said refrigerant has occurred when said leakage detecting means detects leakage of said refrigerant in said machine room. showcase.

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