WO2021074993A1

WO2021074993A1 - Showcase

Info

Publication number: WO2021074993A1
Application number: PCT/JP2019/040632
Authority: WO
Inventors: 杉本　猛; 大林　誠善; 賢一実川; 恵子保坂; 充川島; 千尋田中
Original assignee: 三菱電機株式会社; 三菱電機冷熱応用システム株式会社
Priority date: 2019-10-16
Filing date: 2019-10-16
Publication date: 2021-04-22
Also published as: JP7258174B2; JPWO2021074993A1

Abstract

A showcase equipped with: a refrigerant circuit in which a compressor, a condenser, a metering device and an evaporator are connected by piping and through which a refrigerant circulates; a housing having a storage chamber formed therein which has a plurality of shelves and in which cooling is performed by using the absorbed heat of the evaporator of the refrigerant circuit; a plurality of heating heaters respectively provided to the plurality of shelves in the storage chamber; a condenser fan for ventilating in order to cool the condenser, an operation panel where a drive pattern is inputted; and a control device for controlling the refrigerant circuit according to the drive pattern inputted on the operation panel. The control device drives the condenser fan and performs control so as to increase the ventilation amount from said condenser fan according to the usage duration when the drive pattern inputted on the operation panel is an all-hot operation for turning on all of the plurality of heating heaters or is a stop operation for stopping the compressor of the refrigerant circuit.

Description

Showcase

The present invention relates to a showcase installed in a store such as a supermarket or a convenience store.

Conventionally, showcases for refrigeration or freezing have been installed in stores such as supermarkets and convenience stores. For example, in Patent Document 1, a refrigerating device which is a condensing unit including a compressor and a heat source side heat exchanger, a plurality of drawing devices, and a plurality of indoor heat exchangers connected so as to be a pair thereof. A device in which a plurality of showcases composed of the above are connected by a refrigerant pipe is disclosed.

Japanese Unexamined Patent Publication No. 4-297733

The Freon Emission Control Law, which came into effect in April 2015, stipulates that the global warming potential of the refrigerant used in the refrigerating equipment connected to the showcase must be 1500 or less by 2025. As a refrigerant, a hydrofluorocarbon-based mixed refrigerant such as R404A is used, but the global warming potential of R404A is 3920, which is higher than the value specified by the CFC Emission Control Law. Further, although there is a refrigerant using R410A, the global warming potential of R410A is 2090, which is higher than the value specified by the Freon Emission Control Law. Therefore, it is urgently necessary to implement measures to reduce the total amount of global warming potential.
On the other hand, in the refrigerating apparatus of Patent Document 1, when propane, which is a flammable refrigerant, is used as a refrigerant instead of R404A, the global warming potential of propane is 3.3, which is specified by the Freon Emission Control Law. Fits the numbers. However, when propane is used as a refrigerant in the refrigerating apparatus of Patent Document 1, the amount of propane enclosed is several tens of kg because the indoor units, which are a plurality of showcases, are connected to each other. Further, since propane is a flammable refrigerant, the possibility of reaching the combustion concentration of the refrigerant increases as the amount of propane enclosed increases. Therefore, it is important to ensure safety against refrigerant leakage.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a showcase capable of ensuring safety against leakage of a refrigerant.

The showcase according to the present invention has a refrigerant circuit in which a compressor, a condenser, a drawing device, and an evaporator are connected by a pipe and a refrigerant circulates, and a plurality of shelves, and absorbs heat from the evaporator of the refrigerant circuit. A housing in which a storage chamber to be cooled by using the refrigerant is formed inside, a plurality of heaters provided on the plurality of shelves of the storage chamber, and a condenser that blows air to cool the condenser. A dexterous blower, an operation panel into which an operation pattern is input, and a control device for controlling the refrigerant circuit according to the operation pattern input to the operation panel are provided, and the control device is input by the operation panel. When the operation pattern is all-hot to turn on all of the plurality of heaters or to stop the compressor of the refrigerant circuit, the condenser blower is operated and the amount of air blown by the condenser blower is operated. Is raised and controlled according to the usage time.

According to the present invention, in the case of all-hot indicating the case where all of the plurality of heaters are on or when the refrigerant circulation of the refrigerant circuit is stopped, the blower for the condenser is operated, so that the refrigerant should leak. However, since it is suppressed from diffusing to reach the combustion concentration of the refrigerant, safety against leakage of the refrigerant can be ensured.

It is a schematic diagram which shows the showcase which concerns on Embodiment 1. FIG. It is the schematic which shows the drain water evaporation apparatus of the showcase which concerns on Embodiment 1. FIG. It is a figure which shows the positional relationship between the condenser of the showcase and the blower for a condenser which concerns on Embodiment 1. FIG. It is a figure which shows the operation pattern of each shelf of the showcase which concerns on Embodiment 1. FIG. It is a figure which shows the concentration measurement point at the time of leakage of the propane refrigerant when the showcase which concerns on Embodiment 1 is seen from the front. It is a figure which shows the concentration measurement point at the time of leakage of the propane refrigerant which looked at the showcase which concerns on Embodiment 1 from the upper surface. It is a figure which shows the concentration measurement result of the propane refrigerant at the concentration measurement points E, C and D for each operation pattern of the showcase which concerns on Embodiment 1. FIG. It is a figure which shows the refrigeration cycle of the showcase which concerns on Embodiment 1. FIG. It is a functional block diagram which shows the control function of the blower for a condenser of the control part of the showcase 1 which concerns on Embodiment 1. FIG. It is a schematic diagram which shows the showcase 1 which concerns on Embodiment 2. FIG. It is a figure which shows the structure of the machine room of the showcase which concerns on Embodiment 3.

Hereinafter, the showcase according to the first embodiment will be described with reference to the drawings. In the drawings, the same components will be described with the same reference numerals, and duplicate explanations will be given only when necessary.

Embodiment 1.
FIG. 1 is a schematic view showing a showcase 1 according to the first embodiment. FIG. 2 is a schematic view showing the drain water evaporator 22 of the showcase 1 according to the first embodiment. The showcase 1 of the first embodiment is a showcase with a built-in refrigerator. As shown in FIG. 1, the showcase 1 of the first embodiment is a vertical open showcase, and includes a heat insulating wall 8 having an open front surface and side plates (not shown) attached to both sides of the heat insulating wall 8. Has. Inner layer partition plates 9 are attached to the inside of the heat insulating wall 8 at intervals, and an inner layer duct 10 is formed between the heat insulating wall 8 and the inner layer partition plate 9. Further, the storage chamber 11 is inside the inner layer partition plate 9. The heat insulating wall 8 and the inner layer partition plate 9 are also referred to as a housing.

In this storage room 11, a four-level shelf 12 for displaying products is erected. Fluorescent lamps 13 for lighting are attached to the front portion of the lower surface of each shelf 12 and the ceiling portion 10a of the storage chamber 11. A bottom duct 14 communicating with the inner layer duct 10 is provided below the bottom of the storage chamber 11. Then, an in-compartment blower 15 is installed in the bottom duct 14. Further, an evaporator 5 is vertically installed in the lower part of the inner layer duct 10 located behind the storage chamber 11.

An air outlet 17 is installed on the upper edge of the front opening 16 of the storage chamber 11, and a suction port 18 is attached to the lower edge of the front opening 16. The lower portion of the bottom partition plate 19 forming the bottom surface of the bottom duct 14 is the machine room 20.

The bottom partition plate 19 is provided with a drain pan 21 that receives drain water such as defrost water generated from the evaporator 5. The drain pan 21 is provided with a drain port 21a for dropping the drain water toward the drain water evaporator 22 in the machine room 20.

As shown in FIG. 2, the drain water evaporator 22 includes an evaporating dish 23 for storing drain water, a plurality of evaporation plates 24, and a plurality of support members 27 for integrally supporting the plurality of evaporation plates 24. There is. In FIG. 2, the arrows indicate the wind passing direction. The plurality of evaporation plates 24 are arranged so as to be parallel to the wind passing direction. The plurality of evaporation plates 24 are arranged on the evaporation dish 23. The evaporation plate 24 is made of, for example, a non-woven fabric in which PET (polyethylene terephthalate) and glass fibers are integrated, a porous resin molded product, or the like.

A heater 28 is incorporated in the shelf 12. Each shelf 12 has the uppermost tier, the first tier being AA, the second tier being BB, the third tier being CC, and the fourth tier being DD. In the machine room 20, a compressor 2, a condenser 3, a throttle device 4 which is an electronic expansion valve, a blower 6 for a condenser, and a control device 7 are installed. The condenser blower 6 is arranged on the back side of the condenser 3, that is, on the left side surface side of the condenser 3 as viewed from FIG. FIG. 3 is a diagram showing a positional relationship between the condenser 3 of the showcase 1 and the blower for the condenser 6 according to the first embodiment. The condenser blower 6 blows air to cool the condenser 3. In FIG. 3, the exhaust air of the condenser blower 6 is directed to the right side.

Further, an operation panel 26 for user operation is attached to the outside of the eaves 25 provided on the upper part of the heat insulating wall 8. For example, the operation pattern of the showcase 1 is input to the operation panel 26. The operation pattern will be described later.

The compressor 2, the condenser 3, the drawing device 4, and the evaporator 5 at the top of the bottom partition plate 19 are sequentially connected by a pipe, and the refrigerant circulates in the pipe. The refrigerant discharged from the compressor 2 is radiated to the outside air blown by the condenser blower 6 by the condenser 3, cooled, decompressed by the throttle device 4, evaporated by the evaporator 5, and returned to the compressor 2. By returning, the refrigeration cycle of showcase 1 is formed.

Next, the refrigerant which is the working fluid of the showcase 1 according to the first embodiment will be described.
In the showcase of the first embodiment, as the refrigerant as the working fluid, a flammable refrigerant which is an HC refrigerant having a global warming potential of 1500 or less is used, and for example, propane and isobutane are used. Propane has a global warming potential of 3.3 and isobutane has a global warming potential of 4. In the technical field, the global warming potential is also abbreviated as GWP.

Since the showcase 1 of the actual form 1 is an integrated device including a refrigeration cycle device, it can be miniaturized. Therefore, for example, in the case of propane, the filling amount of the refrigerant can be reduced to about 500 g because the liquid density is small. At the IEC (International Electrotechnical Commission), the upper limit of filling of flammable refrigerant in household and commercial refrigeration equipment was deregulated and increased from 150g to 500g. Therefore, even when a flammable refrigerant having a global warming potential of 1500 or less such as propane is used, it is possible to provide a showcase that satisfies the safety standard against leakage of the refrigerant.

Next, the operation of the showcase 1 according to the first embodiment of the present invention will be described.
When the internal blower 15 is operated, the air in the bottom duct 14 is blown out toward the rear inner layer duct 10, exchanges heat with the evaporator 5, and then blown up from the air outlet 17 on the upper edge of the front opening 16. , Is blown out toward the suction port 18 on the lower edge.

As a result, a cold air air curtain is formed in the front opening 16 of the storage chamber 11, and the intrusion of outside air from the front opening 16 is blocked or suppressed, and a part of the cold air curtain circulates in the storage chamber 11. Then, the inside of the storage chamber 11 is cooled. When the store is closed, the front opening 16 is closed by a night cover 31 (not shown). Then, these cold air and the like return from the suction port 18 to the bottom duct 14, and are sucked into the in-compartment blower 15 again.

During the operation of the showcase 1, drain water such as defrost water from the evaporator 5 falls on the drain pan 21, drain water falls from the drain port 21a onto the evaporation plate 24 of the drain water evaporator 22, and accumulates in the evaporating dish 23. .. The drain water accumulated in the evaporating dish 23 is sucked up by the evaporating plate 24 due to the capillary phenomenon. In addition, in the configuration in which the evaporation plate 24 contains the drain water, the drain water accumulated in the evaporating dish 23 may be sucked up by a pump or the like and sprinkled from above the evaporation plate 24.

Then, the air from the condenser blower 6 passes through the condenser 3 and is warmed, and then flows toward the drain water evaporator 22. The warm air flowing toward the drain water evaporator 22 is applied to the evaporation plate 24 of the drain water evaporator 22, whereby the drain water contained in the evaporation plate 24 evaporates.

The drain water from the evaporator 5 frosts on the evaporator 5 when the showcase is in operation and the temperature inside the refrigerator is about 10 ° C. or lower. As frost formation progresses, the amount of heat exchange in the evaporator 5 decreases and the evaporation performance deteriorates. Therefore, the state of frost formation is detected, and for example, when the compressor 2 operates for a predetermined time, the evaporator 5 is defrosted. carry out. A heater (not shown) is arranged in the evaporator 5, and defrosting is performed by energizing the heater for a predetermined time. When defrosting is performed, the drain water falls on the drain pan 21 as described above, and the drain water falls from the drain port 21a onto the evaporation plate 24 of the drain water evaporator 22 and accumulates in the evaporating dish 23. The evaporating dish 23 may be provided with a float switch (not shown) for detecting the amount of drain water.

FIG. 4 is a diagram showing an operation pattern of each shelf 12 of the showcase 1 according to the first embodiment. As shown in FIG. 4, the first-stage AA, the second-stage BB, the third-stage CC, and the fourth-stage DD of the shelf 12 can handle both hot (heating) and cold (cooling), respectively. The operation patterns of the first stage AA, the second stage BB, the third stage CC, and the fourth stage DD of the shelf 12 can be operated in four patterns of hole hot, second stage hot, one stage hot, and all cold. Further, when the operation is stopped, the stop is instructed as an operation pattern. "Stop" is a stop of the compressor 2. The “cooling operation” is an operation in which at least one of the first-stage AA, the second-stage BB, the third-stage CC, and the fourth-stage DD of the shelf 12 is cooled.

For all hot, two-stage hot, and one-stage hot, the heater 28 built into the corresponding shelf 12 is heated. In all-hot, all the heaters 28 on the shelves 12 of the first-stage AA to the fourth-stage DD are heated.

Except for hole hot, the refrigerant circulates and cools the compressor 2, the condenser 3, the drawing device 4, and the evaporator 5. In FIG. 1, the number of shelves 12 is 4 shelves, but other shelves such as 3 shelves and 5 shelves may be used. The operation pattern is determined by the number of shelves. The internal blower 15 is in operation except when it is all hot, and is stopped when it is all hot.

In the schematic view of the showcase 1 according to the first embodiment shown in FIG. 1, a plurality of holes (not shown) are provided in the inner layer partition plate 9 on the front surface of the evaporator 5 so that cold air can be blown out. It is provided. When the refrigerant leaks from the evaporator 5, the leaked refrigerant may leak from the storage chamber 11 to the outside through a plurality of holes provided in the inner layer partition plate 9 as shown by arrows EE and FF shown in FIG.

Further, the refrigerant leaking from the evaporator 5 may leak into the machine room 20 from the drain port 21a of the drain pan 21. The fluorescent lamp 13, the in-compartment blower 15, and the heater 28, which are the parts in the showcase 1, can be structurally supported so as not to be an ignition source. However, with respect to the refrigerant leaking to the outside of the showcase 1, for example, an outlet outside the showcase 1 may be an ignition source, and it is important to reduce the leakage concentration of the refrigerant outside the showcase 1.

When using propane refrigerant, measure the concentration in the unlikely event that the refrigerant leaks. FIG. 5 is a diagram showing concentration measurement points when the propane refrigerant leaks when the showcase 1 according to the first embodiment is viewed from the front. FIG. 6 is a diagram showing concentration measurement points when the propane refrigerant leaks when the showcase 1 according to the first embodiment is viewed from the upper surface.

In FIGS. 5 and 6, the concentration measurement point indicates the refrigerant concentration measurement point shown from IEC 60335-2-89: 2019. The AFV in FIG. 5 is a front view of the showcase 1, the APB in FIG. 6 is a top view of the showcase 1, and X is the distance from the wall specified by the manufacturer of the

showcase

1 and 50 mm from the wall. Whichever is greater. FL indicates the floor of the test room, R indicates the wall of the test room, A, B, C, D, and E indicate the concentration measurement points, and the asterisk indicates the refrigerant leakage point (evaporator).

When the refrigerant leaks, the method for simulating the refrigerant leak from the refrigerant circuit is shown in JISC9335-2-24 or JISC9335-2-89. A refrigerant leak test was carried out by the method of JISC9335-2-24 or JISC9335-2-89, and the concentrations were measured at the concentration measuring points E, C and D having a high leakage concentration shown in IEC 60335-2-89: 2019.

FIG. 7 is a diagram showing the concentration measurement results of the propane refrigerant at the concentration measurement points E, C and D for each operation pattern of the showcase 1 according to the first embodiment. In FIG. 7, as a condition, a case where the leakage position of the refrigerant is from the evaporator 5 arranged in the refrigerator and a case where the leakage position is from the condenser 3 arranged in the machine room are shown. The operation pattern also shows the case of all cold, one-stage hot, two-stage hot, and all-hot.

The condenser blower 6 uses a DC (Direct current) brushless blower that does not have a brush structure and no internal contact structure, and is being tested at full speed, medium speed, and stop. The internal blower 15 also uses a DC brushless blower and is being tested at full speed and stopped. Since the brush motor electrically opens and closes at the brush portion in the process of rotating the coil, sparks may fly, and care must be taken when using a flammable refrigerant. On the other hand, in a DC brushless blower using a DC brushless motor, since the coil does not rotate and the brush portion does not exist, it does not open and close electrically, and it is safe to use a flammable refrigerant.

The test results show the highest indoor concentration (vol%) at concentration measurement points E, C and D. The amount of refrigerant is 500 g, which is the permissible filling amount of flammable refrigerant revised in IEC 60335-2-89: 2019, and the leakage rate is set to 7.5 kg / h for 4 minutes. The minimum concentration at which flammable gas mixed with air causes combustion by ignition is called the lower combustion limit (LFL). LFL is 2.1 (vol%) in the case of propane.

In the case of all hot, the condenser blower 6 is stopped because the cooling operation is not normally performed, but even if the condenser blower 6 is stopped, the LFL of propane may be exceeded. Further, when the refrigerant leaks from the evaporator 5, even if the refrigerant circuit which is a unit is stopped, if the condenser blower 6 is stopped, the LFL of propane may be exceeded.

Even if the refrigerant leaks from the condenser 3, if it is all hot and the condenser blower 6 is stopped, it may exceed the LFL of propane. Therefore, it is necessary to operate the condenser blower 6 even when the condenser blower 6 is normally stopped at the time of all-hot or when the unit refrigerant circuit is stopped. That is, when the condenser blower 6 is driven at the time of all hot and at the time of stopping, the refrigerant leakage concentration is lower than 2.1 (vol%).

As a path for the refrigerant to leak, the refrigerant leaking from the evaporator 5 is stored as shown in EE and FF in FIG. 1 through a cold air blowing hole (not shown) of the inner layer partition plate 9 on the front surface of the evaporator 5. It may leak from the room 11 to the outside. In this case, when the condenser blower 6 is operating, the leaked refrigerant is agitated and the concentration becomes low.

The refrigerant that may leak from the drain port 21a of the drain pan 21 into the machine room 20 is also agitated when the condenser blower 6 is operating. However, in this case, it is necessary to change the position of the drain port of the drain pan 21, which will be described later. Further, even when the refrigerant leaks from the compressor 2 and the condenser 3 in the machine room 20, the refrigerant is agitated by the condenser blower 6. Then, the refrigerant gradually leaks to the outside from the gap of the housing constituting the machine room 20.

If the refrigerant leaks from the condenser 3, the required air volume of the condenser blower 6 shall be equal to or greater than the blown air volume using the proposed formula of Colbourne. Further, although the number of blowers 6 for the condenser is one, it is possible to provide more safety by using a plurality of blowers 6.

Note that the larger the amount of air blown by the condenser blower 6, the easier it is for the refrigerant leakage concentration to decrease. Further, since the power consumption increases when the amount of air blown by the condenser blower 6 is large, it is optimal to adjust the amount of air blown to such that the refrigerant leakage concentration is less than 2.1 (vol%).

Further, in the showcase 1, even if the condenser blower 6 is operated with the same air volume as the initial operation due to the clogging of the heat exchanger with dust after the operation time elapses, the air volume passing through the condenser 3 is from the initial operation. Will also decrease, exceeding LFL.

In order to deal with such a decrease in the amount of air blown with the passage of the usage time, the amount of air blown by the condenser blower 6 may be controlled to be increased according to the usage time. For example, the relationship between the usage time of the condenser blower 6 and the concentration at the concentration measurement point is obtained in advance, and the operating frequency of the condenser blower 6 is controlled according to the monitoring result of the usage time of the condenser blower 6. You may. Further, the condenser blower 6 may be controlled so as to continue the operation under the condition of the operating frequency at which the blower amount is large in anticipation of a decrease in the blower amount due to the usage time of the condenser blower 6.

Refrigerant leaks from the evaporator 5 when all hot, but the smaller the amount of refrigerant in the evaporator 5, the more the safety of the refrigerant leak is maintained. In this case, the refrigerant exists on the condenser 3 side, but when the refrigerant leaks from the condenser 3, the leaked refrigerant is agitated by the condenser blower 6, so that the concentration does not exceed LFL.

FIG. 8 is a diagram showing a refrigeration cycle of the showcase 1 according to the first embodiment. A refrigeration cycle is formed by communicating the compressor 2, the condenser 3, the squeezing device 4, and the evaporator 5. An evaporator inlet temperature sensor 29 is arranged on the evaporator 5 inlet side. The throttle device 4 is an electronic expansion valve, and when switching from cooling operation to all-hot operation, the throttle device 4 is closed, the compressor 2 continues to operate, and the evaporator inlet temperature sensor 29 should be below a predetermined value of, for example, -30 ° C. For example, a pump-down operation for stopping the compressor 2 is performed. Alternatively, the throttle device 4 is closed, the compressor 2 is operated for a predetermined time, and the pump down operation is performed.

Although it is all hot, the throttle device 4 is closed, but it is conceivable that the refrigerant moves from the condenser 3 side to the evaporator 5 side due to valve leakage in the throttle device 4. In this case, the compressor 2 is operated periodically, for example, once a day, the throttle device 4 is closed, and a pump-down operation is performed so that the refrigerant does not accumulate in the evaporator 5. A low pressure pressure sensor may be used instead of the evaporator inlet temperature sensor 29.

FIG. 9 is a functional block diagram showing a control function of the condenser blower 6 of the control device 7 of the showcase 1 according to the first embodiment. As shown in FIG. 9, the control device 7 includes an operation pattern determination unit 31, a compressor control unit 32, a condenser blower control unit 33, and an in-compression blower control unit 34. The operation pattern determination unit 31 determines the operation pattern input from the operation panel 26.

The compressor control unit 32 stops the operation of the compressor 2 when the operation pattern determination unit 31 determines that the operation pattern input from the operation panel 26 is "all hot" or "stopped". Specifically, the compressor control unit 32 closes the throttle device 4 when the operation pattern input by the operation panel 26 is switched from the cooling operation to the all-hot operation, continues the operation of the compressor 2, and evaporates. When the temperature detected by the vessel inlet temperature sensor 29 is equal to or less than a predetermined value, the operation of the compressor 2 is stopped. When the operation pattern input by the operation panel 26 is all hot, the throttle device 4 is closed, the compressor 2 is continued to operate, and the temperature detected by the evaporator inlet temperature sensor 29 is equal to or less than a predetermined value. Then, the operation of the compressor 2 is stopped.

The condenser blower control unit 33 operates the condenser blower 6 when the operation pattern determination unit 31 determines that the operation pattern input from the operation panel 26 is “all hot” or “stopped”. ..

When the operation pattern determination unit 31 determines that the operation pattern input from the operation panel 26 is "all hot" or "stopped", the internal blower control unit 34 stops the operation of the internal blower 15. ..

Assuming that the directions indicated by the arrows EE and FF in FIG. 1 are the front of the showcase 1, the blower of the condenser 6 is blown from the back side to the front direction. The arrangement of the condenser blower 6 in FIG. 1 is such that the drain water evaporator 22 can be maintained from the front of the showcase 1.

Embodiment 2.
FIG. 10 is a schematic view showing the showcase 1 according to the second embodiment. The same parts as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 10, the condenser 3 and the condenser blower 6 are arranged so as to suck the leaking refrigerant flowing in the refrigerant leak directions EE and FF from the front. The condenser 3 is arranged on the frontmost side of the machine room 20. Next, the condenser blower 6 is arranged on the rear side adjacent to the condenser 3. The condenser blower 6 blows air from the front side to the back side. The drain water evaporator 22 is arranged on the rear side adjacent to the condenser blower 6.

According to the showcase 1 according to the second embodiment, since the condenser 3 and the condenser blower 6 are arranged so as to suck the leaking refrigerant flowing in the refrigerant leakage directions EE and FF from the front, it is easy to suck and stir the leaked refrigerant. Become. Therefore, the rotation speed (air volume) of the condenser blower 6 can be reduced.

The in-flight blower 15 is operating except when it is all hot. Therefore, when cold air flows from the air outlet 17 of FIG. 10 to the suction port 18 to form a cold air curtain and the air speed is 0.88 m / s or more, the amount of the refrigerant leaking to the outside of the showcase 1 is suppressed. , The concentration does not exceed the LFL of the propane refrigerant. However, when the air conditioner is all hot, the air blower 15 is not operating, so that cold air does not flow from the air outlet 17 to the suction port 18, so that the cold air curtain is not formed. Therefore, the blower 6 for the condenser may be operated at the time of all hot, and a heat-resistant night cover 30 capable of withstanding the hole hot may be provided between the outlet 17 and the suction port 18 in FIG. 10 to prevent the refrigerant from leaking. ..

Embodiment 3.
FIG. 11 is a diagram showing the configuration of the machine room 20 of the showcase 1 according to the third embodiment. In FIG. 11, the drain is discharged from the drain port 21a of the drain pan 21 except when it is all hot.

At the time of all hot, the refrigerant leaked between the condenser 3 and the condenser blower 6 is discharged from the drain pan 21 through the drain trap 21c and from the discharge port 21b. During cooling (cold) other than when all hot, the leaked refrigerant is discharged from the drain pan 21 through the drain pipe from the drain port 21a.

Since the drain does not flow when all hot, if the refrigerant leaks, the leaked refrigerant will have a negative pressure at the position of the drain port 21a in FIGS. 1 and 10 because it is behind the condenser blower 6. It may not flow.

In the third embodiment, the discharge port 21b is provided in front of the condenser blower 6. That is, the discharge port 21b is provided on the windward side of the condenser blower 6. This makes it easier for the leaked refrigerant to flow in the showcase 1. Further, in this way, there is a possibility that the rotation speed (air volume) of the condenser blower 6 can be reduced.

Therefore, according to the showcase 1 of the first to third embodiments, it is possible to provide the showcase 1 with a built-in refrigerating device using a flammable refrigerant having a global warming potential of 1500 or less, and no extension pipe is required. The filling amount of the above can be reduced to, for example, 500 g.

Further, according to Showcase 1 of the first to third embodiments, even when a flammable refrigerant having a global warming potential of 1500 or less is used, the leakage of the refrigerant diffuses the leakage of the refrigerant to improve safety against leakage of the refrigerant. The showcase 1 to be secured can be provided.

Furthermore, if the refrigerator and indoor unit (showcase) are separated, it may be difficult to select the installation location because the machine room must be installed in the building due to the increase in the number of refrigerators. is there. However, since the showcase 1 according to the first to third embodiments is a showcase 1 with a built-in refrigerating device and is installed in the store, the installation location of the showcase 1 can be easily selected.

The embodiment is presented as an example and is not intended to limit the scope of the embodiment. The first embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the embodiment. These embodiments and variations thereof are included in the scope and gist of the embodiments.

1 showcase, 2 compressor, 3 condenser, 4 throttle device, 5 evaporator, 6 condenser blower, 7 control device, 8 insulation wall, 9 inner layer partition plate, 10 inner layer duct, 10a ceiling, 11 storage room, 12 shelves, 13 fluorescent lamps, 14 bottom duct, 15 internal blower, 16 front opening, 17 air outlet, 18 suction port, 19 bottom partition plate, 20 machine room, 21 drain pan, 21a drain port, 21b discharge port, 21c Drain trap, 22 Drain water evaporator, 23 Evaporator, 24 Evaporator, 25 Ceiling, 26 Operation panel, 27 Support member, 28 Heater, 29 Evaporator inlet temperature sensor, 30 Night cover, 31 Operation pattern judgment unit, 32 Compressor control unit, 33 condenser blower control unit, 34 internal blower control unit, A, B, C, D, E concentration measurement points, EE, FF refrigerant leakage direction, AA 1st stage, BB 2nd stage, CC 3rd stage, DD 4th stage.

Claims

A refrigerant circuit in which a compressor, a condenser, a throttle device, and an evaporator are connected by piping and a refrigerant circulates.
A housing having a plurality of shelves and having a storage chamber internally formed for cooling by utilizing the endothermic heat of the evaporator of the refrigerant circuit.
A plurality of heaters provided on the plurality of shelves in the storage chamber, and
A condenser blower that blows air to cool the condenser,
The operation panel where the operation pattern is input and
A control device for controlling the refrigerant circuit according to the operation pattern input to the operation panel is provided.
When the operation pattern input by the operation panel is all-hot to turn on all of the plurality of heaters or to stop the compressor of the refrigerant circuit, the control device uses the condenser blower. A showcase that operates and controls the amount of air blown by the compressor blower according to the usage time.
A plurality of blowers for the condenser are provided.
The showcase according to claim 1.
A heat-resistant night cover capable of withstanding the all-hot is further provided between the outlet and the suction port of the storage chamber.
The showcase according to claim 1 or 2.
A drain pan that receives the drain water generated from the evaporator and
A drain water evaporator for evaporating the drain water from the drain pan is further provided.
The blower for the condenser is arranged between the condenser and the drain water evaporator, and blows air to the drain water evaporator.
The showcase according to any one of claims 1 to 3.
The drain pan outlet is provided on the windward side of the condenser blower.
The showcase according to any one of claims 1 to 4.
Further provided with an internal blower that communicates with the inner layer duct in which the evaporator is installed and is installed in the bottom duct formed in the lower part of the front storage chamber.
The control device stops the operation of the in-compartment blower when the operation pattern input by the operation panel is the all-hot or the stop.
The showcase according to any one of claims 1 to 5.