JP2021089113A - Showcase - Google Patents

Abstract

To provide a showcase capable of reducing a leakage amount of refrigerant even in a case where the refrigerant leaks on a storage chamber side of a refrigerant circuit during a heat insulation operation in which air circulation in the storage chamber is stopped.SOLUTION: A showcase comprises: a refrigerant circuit in which a compressor, a condenser, an expansion valve, and an evaporator are connected in an order by a refrigerant pipe; a heater that keeps a storage in a storage chamber warm; blocking means that is provided in the refrigerant piping between the condenser and the evaporator, and can block a flow of refrigerant; and a control device that controls the compressor, the heater and the blocking means. The evaporator is arranged in an air passage reaching the inside of the storage chamber through a blowout port. The compressor and the condenser are arranged in a machine chamber. The control device performs, before starting heat retention by the heater, a recovery operation in which the compressor is operated in a state where the flow of the refrigerant is blocked by the blocking means to recover the refrigerant to the machine chamber side of the refrigerant circuit, and then starts heat insulation by the heater.SELECTED DRAWING: Figure 1

Description

The present invention relates to a showcase.

In the showcase, there are display shelves provided in the storage chamber inside the case body for displaying products, and a circulation means for circulating the air inside the storage chamber between the storage chamber and the air passage. It is known that a cooling means for cooling the air circulated by the circulation means and a heating means provided on the display shelf are provided and the heating means is driven in a state where the driving of the cooling means and the circulation means is stopped. (See, for example, Patent Document 1).

JP-A-2017-225551

As described above, in the showcase as shown in Patent Document 1, when heating is performed by the heating means (heater) provided on the display shelf, the circulation of air inside the storage chamber (storage chamber) is stopped. .. Therefore, if the refrigerant leaks on the storage chamber side of the refrigerant circuit as a cooling means for cooling the air during heating by the heater, the leaked refrigerant does not diffuse and stays in the storage chamber, around the showcase, or the like. A region where the refrigerant concentration is above a certain level may be formed.

The present invention has been made to solve such a problem. The purpose is to provide a refrigerant circuit for cooling the storage chamber and a heater for heating the storage chamber, and in a showcase where the heater heats the storage chamber to keep it warm and stops the circulation of air in the storage chamber during the heat retention operation. When the refrigerant leaks on the storage chamber side of the refrigerant circuit during the heat retention operation, it is possible to reduce the amount of the refrigerant leaked, and as a result, the leaked refrigerant stays and a region where the refrigerant concentration exceeds a certain level is formed. The purpose is to provide a showcase that can suppress this.

The showcase according to the present invention includes a refrigerant circuit in which a compressor, a condenser, an expansion valve, and an evaporator are connected in order by a refrigerant pipe filled with a refrigerant, and a heater for keeping the storage in the storage chamber warm. The refrigerant pipe between the condenser and the evaporator is provided with a blocking means capable of blocking the flow of the refrigerant, and a control device for controlling the compressor, the heater and the blocking means. The evaporator is arranged in an air passage communicating with the inside of the storage chamber through an air outlet, the compressor and the condenser are arranged in the machine chamber, and the control device keeps heat by the heater. Before starting the operation, the compressor is operated in a state where the flow of the refrigerant is blocked by the blocking means to perform a recovery operation for recovering the refrigerant to the machine room side of the refrigerant circuit, and then the heater. Start heat retention by.

Alternatively, the showcase according to the present invention is for keeping the storage in the storage chamber warm and the refrigerant circuit in which the compressor, the condenser, the expansion valve and the evaporator are connected in order by the refrigerant pipe filled with the refrigerant. A heater, a blocking means provided in the refrigerant pipe between the condenser and the evaporator and capable of blocking the flow of the refrigerant, and a control device for controlling the compressor, the heater and the blocking means. The evaporator is arranged in an air passage communicating with the inside of the storage chamber through an air outlet, the compressor and the condenser are arranged in the machine chamber, and the control device is the heater. Before starting the heat retention by the above, the compressor is operated in a state where the flow of the refrigerant is blocked by the blocking means to start a recovery operation for recovering the refrigerant to the machine room side of the refrigerant circuit. The heat retention by the heater is started during the recovery operation.

Alternatively, the showcase according to the present invention is for keeping the storage in the storage chamber warm and the refrigerant circuit in which the compressor, the condenser, the expansion valve and the evaporator are connected in order by the refrigerant pipe filled with the refrigerant. A heater, a blocking means provided in the refrigerant pipe between the condenser and the evaporator and capable of blocking the flow of the refrigerant, and a control device for controlling the compressor, the heater and the blocking means. The evaporator is arranged in an air passage communicating with the inside of the storage chamber through an air outlet, the compressor and the condenser are arranged in the machine chamber, and the control device is the heater. After starting the heat retention by the above, the compressor is operated in a state where the flow of the refrigerant is blocked by the blocking means to perform a recovery operation for recovering the refrigerant to the machine room side of the refrigerant circuit. ..

According to the showcase according to the present invention, when the refrigerant leaks on the storage chamber side of the refrigerant circuit during the heat retention operation, it is possible to reduce the amount of the refrigerant leak.

It is a figure which shows typically the whole structure of the showcase which concerns on Embodiment 1 of this invention. It is a block diagram which shows the structure of the control system of the showcase which concerns on Embodiment 1 of this invention. It is a flow chart which shows an example of the operation of the showcase which concerns on Embodiment 1 of this invention. It is a figure which shows typically the modification of the structure of the showcase which concerns on Embodiment 1 of this invention. It is a figure which shows typically the modification of the structure of the showcase which concerns on Embodiment 1 of this invention. It is a figure which shows typically the modification of the structure of the showcase which concerns on Embodiment 1 of this invention. It is a flow figure which shows another example of the operation of the showcase which concerns on Embodiment 1 of this invention.

A mode for carrying out the present invention will be described with reference to the accompanying drawings. In each figure, the same or corresponding parts are designated by the same reference numerals, and duplicate description will be appropriately simplified or omitted. In the following description, for convenience, the positional relationship of each structure may be expressed with reference to the illustrated state. The present invention is not limited to the following embodiments, and can be variously modified without departing from the spirit of the present invention.

Embodiment 1.
Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 7. FIG. 1 is a diagram schematically showing the overall configuration of a showcase. FIG. 2 is a block diagram showing a configuration of a showcase control system. FIG. 3 is a flow chart showing an example of the operation of the showcase. 4 to 6 are diagrams schematically showing a modified example of the configuration of the showcase. FIG. 7 is a flow chart showing another example of the operation of the showcase.

The showcase 100 according to this embodiment is an open showcase that is installed in a supermarket, a convenience store, or the like to store and display beverages, foods, and the like. The showcase 100 may be a closed (reach-in) showcase provided with a door for opening and closing the storage room.

As shown in FIG. 1, the showcase 100 includes a housing 1. The housing 1 has a rectangular parallelepiped box shape as a whole. A storage room 3 and a machine room 2 are formed in the housing 1. The storage chamber 3 is arranged on the upper side of the housing 1. The lower side of the housing 1 is a machine room 2. The configuration example described here is a so-called integrated showcase 100 in which a storage room 3 and a machine room 2 are provided in one housing 1. However, the present invention is not limited to this configuration, and the storage chamber 3 and the machine chamber 2 may be provided in separate housings.

The storage room 3 is a space in which storages such as beverages and fresh foods to be cooled can be stored. A plurality of display shelves 4 for displaying fresh foods and the like are arranged and attached in the storage room 3 in the vertical direction. An opening 5 is formed on at least one surface of the storage chamber 3. Then, food can be taken in and out of the display shelf 4 through the opening 5. In the configuration example described here, there is an opening 5 on the front surface of the storage chamber 3. That is, the storage chamber 3 is opened at the front surface of the housing 1.

The showcase 100 includes a refrigerant circuit. As shown in FIG. 1, the refrigerant circuit is configured such that the compressor 11, the condenser 12, the expansion valve 13, and the evaporator 14 are cyclically connected by the refrigerant pipe 17 in this order. Refrigerant is sealed in the refrigerant circuit including the refrigerant pipe 17 and the like.

From the viewpoint of protecting the global environment, it is desirable to use a refrigerant having a small global warming potential (GWP) as the refrigerant enclosed in the refrigerant circuit. Further, the refrigerant sealed in the refrigerant circuit is flammable. This refrigerant has a higher average molecular weight than air. That is, the refrigerant has a higher density than air and is heavier than air under atmospheric pressure. Therefore, the refrigerant has the property of sinking downward in the direction of gravity in the air.

Specific examples of such a refrigerant include tetrafluoropropene (CF3CF = CH2: HFO-1234yf), difluoromethane (CH2F2: R32), propane (R290), propylene (R1270), ethane (R170), and butane (R600). ), Isobutane (R600a), 1.1.1.2-Tetrafluoroethane (C2H2F4: R134a), Pentafluoroethane (C2HF5: R125), 1.3.3.3-Tetrafluoro-1-propene (CF3-). A (mixed) refrigerant composed of one or more refrigerants selected from CH = CHF: HFO-1234ze), carbon dioxide (CO2: R744), and the like can be used.

The compressor 11 compresses the refrigerant to increase the pressure and temperature of the refrigerant. The compressed refrigerant is discharged from the compressor 11. As the compressor 11, for example, a rotary compressor, a scroll compressor, a reciprocating compressor, or the like can be used.

The condenser 12 exchanges heat between the refrigerant discharged from the compressor 11 and the surrounding air, dissipates heat from the refrigerant, and condenses the refrigerant. The condenser fan 15 sends out the air heated by the condenser 12 and also sends new air around the condenser 12 to promote heat exchange in the condenser 12.

The expansion valve 13 expands the refrigerant condensed by the condenser 12 and depressurizes the refrigerant. In the configuration example described here, the expansion valve 13 is a linear electronic expansion valve (LEV: Linear Electrical expansion Valve). Therefore, by closing the expansion valve 13, the flow of the refrigerant can be blocked.

The evaporator 14 exchanges heat between the refrigerant decompressed by the expansion valve 13 and the surrounding air, and causes the refrigerant to absorb heat to evaporate. At this time, the air that has exchanged heat with the refrigerant is cooled. That is, the evaporator 14 acts as a cooler. The evaporator fan 16 sends out the air cooled by the evaporator 14 as a cooler, and also sends new air around the evaporator 14 to promote heat exchange in the evaporator 14.

A steam compression refrigeration cycle is realized by circulating the refrigerant through the refrigerant circuit configured as described above. The refrigeration cycle realized by this refrigerant circuit acts as a heat pump that transfers heat between the evaporator 14 side and the condenser 12 side. The evaporator fan 16 and the condenser fan 15 are, for example, a propeller fan, a line flow fan, a sirocco fan, and the like.

A compressor 11, a condenser 12, a condenser fan 15, and an expansion valve 13 are housed inside the machine room 2. An air supply port 31 and an exhaust port 32 are formed in the machine room 2. The air supply port 31 is an opening for introducing outside air into the machine room 2. The exhaust port 32 is an opening for discharging the air that has passed through the condenser 12 to the outside of the machine room 2. In the configuration example described here, the air supply port 31 is arranged on the same side as the opening 5 of the storage chamber 3, that is, on the front surface of the housing 1. The exhaust port 32 is arranged on the opposite side of the air supply port 31, that is, on the back surface of the housing 1.

Inside the machine room 2, a machine room air passage leading from the air supply port 31 to the exhaust port 32 is formed. The condenser 12 and the condenser fan 15 are arranged in the machine room air passage. The condenser fan 15 is a fan that generates an air flow passing through the condenser 12 in the air passage in the machine room.

An air outlet 22 and a suction port 21 are formed in the storage chamber 3. The housing 1 is provided with a storage chamber air passage from the suction port 21 to the air outlet 22. This storage chamber air passage is separated from the storage chamber 3. An evaporator 14 and an evaporator fan 16 are housed in the storage chamber air passage. That is, the evaporator 14 is arranged in the storage chamber air passage that communicates with the inside of the storage chamber 3 via the air outlet 22. Then, the evaporator fan 16 generates an air flow passing through the evaporator 14 in the storage chamber air passage.

When the evaporator fan 16 is driven, the cold air generated through the evaporator 14 is blown out from the outlet 22 into the storage chamber 3. The air outlet 22 is opened downward at the front end of the upper inner wall surface of the storage chamber 3 so as to face the storage chamber 3. The cold air blown out from the air outlet 22 descends along the opening surface of the opening 5. As a result, a cold air curtain is formed in the opening 5 of the storage chamber 3. A part of the air in the storage chamber 3 is sucked from the suction port 21. The air sucked from the suction port 21 is cooled by the evaporator 14 when passing through the storage chamber air passage, and is blown out into the storage chamber 3 again from the outlet 22.

The showcase 100 includes a heater 19. The heater 19 is for keeping the stored matter in the storage chamber 3 warm. In the configuration example described here, the heater 19 is provided on the lower surface of each display shelf 4. When the heater 19 is energized, the heater 19 generates heat and heats the stored items placed on the display shelf 4, so that the stored items can be kept warm.

The showcase 100 of this embodiment includes a check valve 18. The check valve 18 is provided in the refrigerant pipe 17 between the evaporator 14 and the compressor 11. The check valve 18 allows the flow of the refrigerant in only one direction. In this embodiment, the refrigerant can flow only from the evaporator 14 to the compressor 11. That is, the check valve 18 allows the flow of the refrigerant from the evaporator 14 to the compressor 11. Then, the check valve 18 prohibits the flow of the refrigerant from the compressor 11 to the evaporator 14. By providing such a check valve 18, even if the operation of the compressor 11 is stopped and the flow of the refrigerant in the refrigerant circuit is stopped, the refrigerant does not flow from the compressor 11 to the evaporator 14.

As described above, the flow of the refrigerant can be blocked by closing the expansion valve 13. That is, the expansion valve 13 constitutes a blocking means capable of blocking the flow of the refrigerant. More specifically, in this embodiment, the expansion valve 13 also serves as a blocking means. The expansion valve 13 as a blocking means is provided in the refrigerant pipe 17 between the condenser 12 and the evaporator 14. As a blocking means, a shutoff valve different from the expansion valve 13 may be provided in the refrigerant pipe 17 between the condenser 12 and the evaporator 14.

Next, the configuration of the control system of the showcase 100 of this embodiment will be described with reference to FIG. As shown in the figure, the showcase 100 includes a control device 50. The control device 50 controls the overall operation of the showcase 100. Specifically, the control device 50 controls the operations of the compressor 11, the condenser fan 15, the evaporator fan 16, and the heater 19. Further, the control device 50 also controls the operation of the expansion valve 13 as the above-mentioned blocking means.

The showcase 100 can be subjected to normal refrigeration or freezing operation (hereinafter, also simply referred to as “normal operation”) and heat retention operation. The normal operation is an operation of cooling the stored matter in the storage chamber 3. The heat retention operation is an operation of heating and keeping warm the stored matter in the storage chamber 3. During normal operation, the control device 50 opens the expansion valve 13 to operate the compressor 11, the condenser fan 15, and the evaporator fan 16. In normal operation, the control device 50 stops energization of the heater 19.

On the other hand, when the heat retaining operation is performed, the control device 50 energizes the heater 19. In the heat retention operation, the control device 50 stops the operation of the compressor 11 and the evaporator fan 16. The condenser fan 15 may or may not be operated during the heat retention operation.

Further, the showcase 100 of this embodiment can perform a recovery operation in addition to the above-mentioned normal operation and heat retention operation. The recovery operation is an operation of recovering the refrigerant in the refrigerant circuit to the machine room 2 side of the refrigerant circuit. In the recovery operation, the control device 50 first blocks the flow of the refrigerant by the above-mentioned blocking means. In the configuration example described here, the control device 50 closes the expansion valve 13. Then, the control device 50 operates the compressor 11. As a result, the refrigerant on the evaporator 14 side of the storage chamber 3 is sucked out to the compressor 11.

The high-temperature gas-phase refrigerant discharged from the compressor 11 passes through the condenser 12 and exchanges heat with air. The gas phase refrigerant is liquefied by this heat exchange. The liquefied refrigerant passes through the condenser 12 and reaches the expansion valve 13. At this time, since the expansion valve 13 is closed, the liquid phase refrigerant is mainly the refrigerant in the refrigerant pipe 17 between the compressor 11 and the condenser 12, and the refrigerant between the condenser 12 and the expansion valve 13. It is collected in the pipe 17 and in the condenser 12.

Then, when the preset reference time elapses after the recovery operation is started, the control device 50 stops the operation of the compressor 11 and ends the recovery operation. The reference time at this time takes into consideration the time required to move the refrigerant to the machine room 2 side based on the specifications of the showcase 100 such as the filling amount of the refrigerant sealed in the refrigerant circuit and the capacity of the compressor 11. It can be decided by doing.

As described above, the check valve 18 is provided in the configuration example described here. Therefore, even if the compressor 11 is left stopped after the recovery operation is completed, the refrigerant does not flow back from the compressor 11 to the evaporator 14. It should be noted that the inside of the compressor 11 is generally provided with a structure such as a valve for preventing backflow. Therefore, in such a case, the check valve 18 may be omitted. However, from the viewpoint of more reliably preventing the backflow of the recovered refrigerant on the machine room 2 side, it is desirable to provide the check valve 18.

In the showcase 100 of this embodiment, when the heat retaining operation is performed, the heat retaining operation is started after the recovery operation is performed. That is, the control device 50 performs a recovery operation before starting the heat retention by the heater 19. Then, the control device 50 starts heat retention by the heater 19 after the recovery operation is completed.

As described above, the condenser fan 15 and the evaporator fan 16 are operating during the normal operation of the showcase 100. Therefore, in either the machine room 2 side or the storage room 3 side, when the refrigerant leaks from the refrigerant circuit, the leaked refrigerant is diffused by stirring with the air flow by the condenser fan 15 or the evaporator fan 16. It is possible to prevent the leakage refrigerant from staying and forming a region where the refrigerant concentration exceeds a certain level.

On the other hand, during the heat retention operation of the showcase 100, the evaporator fan 16 is stopped as described above. Therefore, particularly when the refrigerant leaks from the refrigerant circuit on the storage chamber 3 side, the leaked refrigerant does not diffuse and stays, and a region where the refrigerant concentration becomes a certain level or more is likely to be formed. According to the showcase 100 of this embodiment, by starting the heat-retaining operation after performing the recovery operation, even if the refrigerant circuit on the storage chamber 3 side is broken or corroded during the heat-retaining operation, the refrigerant leaks. It is possible to suppress the refrigerant leakage or minimize the refrigerant leakage. Therefore, in the showcase 100 that stops the circulation of air in the storage chamber 3 during the heat retention operation, it is possible to reduce the amount of refrigerant leakage when the refrigerant leaks on the storage chamber 3 side of the refrigerant circuit during the heat retention operation. Therefore, it is possible to prevent the leaking refrigerant from staying and forming a region where the refrigerant concentration exceeds a certain level. As described above, the condenser fan 15 may or may not be operated during the heat retention operation, but if the condenser fan 15 is operated during the heat retention operation, the refrigerant leaks from the refrigerant circuit on the machine room 2 side. When it occurs, it can be agitated by the air flow by the condenser fan 15 to diffuse the leaking refrigerant.

The control device 50 may operate one or both of the evaporator fan 16 and the condenser fan 15 during the recovery operation. By doing so, when the refrigerant leaks from the refrigerant circuit during the recovery operation, the leaked refrigerant is diffused, and it is possible to prevent the leaked refrigerant from staying and forming a region where the refrigerant concentration exceeds a certain level. .. Further, when the condenser fan 15 is operated during the recovery operation, it is further preferable that the control device 50 operates the condenser fan 15 at a higher rotation speed than during the normal operation during the recovery operation. By doing so, the heat exchange efficiency in the condenser 12 can be improved and the refrigerant can promote liquefaction. Therefore, the time required for the recovery operation can be shortened, and the recovery of the refrigerant can be completed in a shorter time.

Next, an example of the operation of the recovery operation and the heat retention operation in the showcase 100 configured as described above will be described with reference to the flow chart of FIG. When the showcase 100 during normal operation starts the recovery operation, first, in step S1, the control device 50 continues the operation of the condenser fan 15 and the evaporator fan 16 as they are.

In the following step S2, the control device 50 closes the expansion valve 13 as the blocking means described above to prevent the flow of the refrigerant at the location where the expansion valve 13 is provided. In the following step S3, the control device 50 operates the compressor 11. After step S3, the process proceeds to step S4.

In step S4, the control device 50 confirms whether or not the above-mentioned reference time has elapsed since the recovery operation was started. If the above-mentioned reference time has not elapsed since the recovery operation was started, the process returns to step S3 and the operation of the compressor 11 is continued. Then, when the above-mentioned reference time elapses after the recovery operation is started, the process proceeds from step S4 to step S5.

In step S5, the control device 50 stops the compressor 11. In the following step S6, the control device 50 stops the evaporator fan 16 and ends the recovery operation. Then, the process proceeds to step S7, and the control device 50 energizes the heater 19 to start the heat retaining operation. When the process of step S7 is completed, the series of operations ends.

Next, a modified example of the showcase 100 configured as described above will be described with reference to FIGS. 4 and 5. In the configuration examples described so far, the end condition of the recovery operation is determined by the elapsed time from the start of the recovery operation. In the modified examples shown in FIGS. 4 and 5, the end condition of the recovery operation is determined by using the detection result of the sensor.

First, a modified example shown in FIG. 4 will be described with reference to the same figure. In this modification, the showcase 100 includes a temperature sensor 41. The temperature sensor 41 is a sensor that detects the temperature of the condenser 12. The temperature of the condenser 12 referred to here is the surface temperature of the condenser 12 or the temperature of the refrigerant circulating in the condenser 12. Then, after the recovery operation is started, the control device 50 stops the compressor 11 and ends the recovery operation when the temperature of the condenser 12 detected by the temperature sensor 41 becomes equal to or lower than a preset reference temperature.

Next, a modified example shown in FIG. 5 will be described with reference to the same figure. In this modification, the showcase 100 includes a pressure sensor 42. The pressure sensor 42 is provided in the refrigerant pipe 17 between the evaporator 14 and the check valve 18. Then, the pressure sensor 42 detects the pressure of the refrigerant in the refrigerant pipe 17 between the evaporator 14 and the check valve 18.

When the operation of the compressor 11 is continued in the recovery operation, the pressure on the suction side of the compressor 11 gradually decreases as the refrigerant is recovered. Therefore, the control device 50 recovers when the pressure detected by the pressure sensor 42, that is, the pressure of the refrigerant in the refrigerant pipe 17 on the evaporator 14 side becomes equal to or lower than a preset reference pressure after the start of the recovery operation. End the operation. By lowering the value of the reference pressure at which the recovery operation ends as much as possible, more refrigerant can be moved from the storage chamber 3 side to the machine chamber 2 side. Therefore, the value of the reference pressure at which the recovery operation is completed may be set to the minimum pressure allowed for the operation of the compressor 11.

In the modified example shown in FIG. 5, when the normal operation is restarted after the recovery operation, the control device 50 prohibits the restart of the normal operation when the pressure detected by the pressure sensor 42 is larger than the above-mentioned reference pressure. You may try to do so. As described above, the pressure in the refrigerant pipe 17 on the evaporator 14 side should have been equal to or lower than the reference pressure at the end of the recovery operation. The fact that the pressure became higher than the reference pressure when the normal operation was restarted means that the refrigerant circuit on the evaporator 14 side, that is, the storage chamber 3 side was broken or corroded, and outside air entered the refrigerant pipe 17. There is a possibility that the pressure in the refrigerant pipe 17 has increased. Therefore, when the pressure detected by the pressure sensor 42 at the time of resuming the normal operation is larger than the above-mentioned reference pressure, the control device 50, for example, keeps the expansion valve 13 as the above-mentioned blocking means closed and operates the normal operation. Prohibit resumption.

In the configuration example described above, both the opening 5 of the storage chamber 3 and the air supply port 31 of the machine room 2 are arranged on the front surface of the housing 1. Therefore, during the heat retention operation in which the evaporator fan 16 is stopped, a refrigerant leak occurs in the refrigerant circuit on the storage chamber 3 side, and the leaked refrigerant leaks to the outside of the showcase 100 from the opening 5 of the storage chamber 3. In this case, if the condenser fan 15 is operating, it can be said that the refrigerant leaked to the outside of the showcase 100 is easily sucked into the machine room 2 from the air supply port 31 and diffused.

However, as described above, according to the showcase 100 of this embodiment, since the refrigerant is collected on the machine room 2 side during the heat retention operation, the air supply port 31 and the exhaust port 32 of the machine room 2 are respectively. May be arranged on any of the left side surface, the right side surface, and the back surface of the housing 1. For example, FIG. 6 shows a case where the air supply port 31 and the exhaust port 32 of the machine room 2 are arranged on the side surface of the housing 1. By doing so, since the air supply port 31 and the exhaust port 32 of the machine room 2 are not provided on the front surface of the housing 1 having the opening 5 of the storage room 3, the design of the appearance of the showcase 100 can be improved. Further, on the side of the storage chamber 3 having the opening 5, dust, foreign matter, and the like are likely to fly by taking things in and out of the storage chamber 3. By arranging the air supply port 31 and the exhaust port 32 of the machine room 2 on the surface of the housing 1 different from the side where the opening 5 of the storage room 3 is located as in the example of FIG. 6, dust, foreign matter, etc. are supplied. It is possible to suppress the invasion into the machine room 2 from the air port 31 and the exhaust port 32.

Instead of starting the heat retention operation after the recovery operation is completed, the heat retention operation may be started after the recovery operation is started and before the recovery operation is completed. That is, before starting the heat retention by the heater 19, the control device 50 first blocks the flow of the refrigerant by the above-mentioned blocking means, and operates the compressor 11 in a state where the flow of the refrigerant is blocked to use the refrigerant as the refrigerant. The recovery operation for recovery is performed on the machine room 2 side of the circuit. Then, the control device 50 may start heat retention by the heater 19 during this recovery operation. Even in this case, the amount of refrigerant on the storage chamber 3 side of the refrigerant circuit can be reduced at the start of the heat retention operation as compared with before the start of the recovery operation. Therefore, even if a refrigerant leak occurs on the storage chamber 3 side of the refrigerant circuit during the heat retention operation before the end of the recovery operation, a certain effect can be obtained in reducing the amount of the refrigerant leak.

Further, instead of starting the heat retaining operation after the recovery operation is completed, the heat retaining operation may be started before the recovery operation is started. That is, the control device 50 first starts heat retention by the heater 19, then blocks the flow of the refrigerant by the above-mentioned blocking means, and operates the compressor 11 in a state where the flow of the refrigerant is blocked to charge the refrigerant. The recovery operation for recovery is started on the machine room 2 side of the refrigerant circuit. Even in this case, the amount of refrigerant on the storage chamber 3 side of the refrigerant circuit can be reduced during the heat retention operation as compared with before the start of the recovery operation. Therefore, even if a refrigerant leak occurs on the storage chamber 3 side of the refrigerant circuit during the heat retention operation before the end of the recovery operation, a certain effect can be obtained in reducing the amount of the refrigerant leak. Further, by starting the energization of the heater 19 before the recovery operation, it is possible to obtain the heat retaining effect of the storage chamber 3 at an early stage.

Further, when the check valve 18 is provided in the refrigerant pipe 17 between the compressor 11 and the evaporator 14, the indirect evaporator 14 by the heater 19 is used without operating the compressor 11 in the recovery operation. The refrigerant on the storage chamber 3 side of the refrigerant circuit may be moved to the machine room 2 side of the refrigerant circuit by utilizing the heating action. Next, an example of the operation of the showcase 100 in this case will be described with reference to the flow chart of FIG. First, in step S11, the control device 50 continues the operation of the condenser fan 15 and the evaporator fan 16.

In the following step S12, the control device 50 closes the expansion valve 13 as the blocking means described above to prevent the flow of the refrigerant at the location where the expansion valve 13 is provided. In the following step S13, the control device 50 stops the compressor 11. After step S13, the process proceeds to step S14.

In step S14, the control device 50 starts energizing the heater 19. By energizing the heater 19, the air in the storage chamber 3 is heated. Then, the evaporator fan 16 allows the warmed air in the storage chamber 3 to pass through the evaporator 14 to heat the evaporator 14. Then, the refrigerant in the evaporator 14 is heated and the pressure rises. Since the expansion valve 13 is closed in step S12, the refrigerant on the evaporator 14 side passes through the check valve 18 and flows to the compressor 11 side. The check valve 18 blocks the flow of the refrigerant from the compressor 11 side to the evaporator 14 side. Therefore, the refrigerant moves from the storage chamber 3 side of the refrigerant circuit to the machine room 2 side.

In the following step S15, the control device 50 confirms whether or not a preset time has elapsed since the energization of the heater 19 was started in step S14. Then, when a preset time has elapsed since the energization of the heater 19 was started, the process proceeds to step S16. In the following step S16, the control device 50 stops the evaporator fan 16, and the showcase 100 completely shifts to the heat retention operation. When the process of step S16 is completed, the series of operations ends.

Also in the operation example shown in FIG. 7, the amount of refrigerant on the storage chamber 3 side of the refrigerant circuit during the heat retention operation can be reduced as compared with the normal operation. Therefore, a certain effect can be obtained in reducing the amount of refrigerant leakage when the refrigerant leaks on the storage chamber 3 side of the refrigerant circuit during the heat retention operation.

In each configuration example of the showcase 100 described above, the expansion valve 13 may be a solenoid valve that closes when there is no energization. As a result, when a refrigerant leaks on the storage chamber 3 side of the refrigerant circuit during a power failure, the refrigerant in the refrigerant circuit on the machine room 2 side of the expansion valve 13 and the check valve 18 is prevented from leaking and evaporates. If the vessel 14 is broken or corroded, the entire amount of the refrigerant in the refrigerant circuit leaks. However, by installing a solenoid valve that closes when the power is off, the amount of the leaking refrigerant can be reduced.

1 Housing 2 Machine room 3 Storage room 4 Display shelf 5 Opening 6 Heater 11 Compressor 12 Condenser 13 Expansion valve 14 Evaporator 15 Condenser fan 16 Evaporator fan 17 Refrigerant piping 18 Check valve 19 Heater 21 Suction port 22 Blow Outlet 31 Air supply port 32 Exhaust port 41 Temperature sensor 42 Pressure sensor 50 Control device 100 Showcase

The showcase according to the present invention is for keeping warmth of a refrigerant circuit in which a compressor, a condenser, an expansion valve and an evaporator are connected in order by a refrigerant pipe filled with a refrigerant, and a storage in an open storage chamber. Heater, a blocking means provided in the refrigerant pipe between the condenser and the evaporator and capable of blocking the flow of the refrigerant, and a control device for controlling the compressor, the heater and the blocking means. The evaporator is arranged in an air passage communicating with the inside of the storage chamber through an air outlet, the compressor and the condenser are arranged in the machine chamber, and the heater is the storage. An evaporator fan, which is provided on a shelf on which indoor storage is placed and is arranged in the air passage to generate an air flow through the evaporator, and air which is arranged in the machine chamber and passes through the condenser. Further including a condenser fan for generating a flow, the control device operates the compressor in a state where the flow of the refrigerant is blocked by the blocking means before starting heat retention by the heater. after performing the recovery operation for recovering the refrigerant in the machine chamber side of the refrigerant circuit, to initiate thermal insulation by the heater, the evaporator fan, it is stopped at the time kept by the heater.

Alternatively, in the showcase according to the present invention, a refrigerant circuit in which a compressor, a condenser, an expansion valve, and an evaporator are connected in order by a refrigerant pipe filled with a refrigerant and a storage in an open storage chamber are kept warm. A heater for controlling the compressor, a blocking means provided in the refrigerant pipe between the condenser and the evaporator and capable of blocking the flow of the refrigerant, and a control for controlling the compressor, the heater and the blocking means. The evaporator is provided with an apparatus, the evaporator is arranged in an air passage communicating with the inside of the storage chamber through an air outlet, the compressor and the condenser are arranged in a machine chamber, and the heater is. An evaporator fan, which is provided on a shelf on which the storage in the storage chamber is placed and is arranged in the air passage to generate an air flow passing through the evaporator, and an evaporator fan which is arranged in the machine chamber and passes through the condenser. Further including a condenser fan for generating an air flow to be generated, the control device operates the compressor in a state where the flow of the refrigerant is blocked by the blocking means before the heat retention by the heater is started. to start the recovery operation for recovering the refrigerant in the machine chamber side of the refrigerant circuit Te, said to start warming by a heater during the recovery operation, the evaporator fan, you are stopped at the time kept by the heater.

Alternatively, in the showcase according to the present invention, a refrigerant circuit in which a compressor, a condenser, an expansion valve, and an evaporator are connected in order by a refrigerant pipe filled with a refrigerant and a storage in an open storage chamber are kept warm. A heater for controlling the compressor, a blocking means provided in the refrigerant pipe between the condenser and the evaporator and capable of blocking the flow of the refrigerant, and a control for controlling the compressor, the heater and the blocking means. The compressor and the condenser are arranged in the machine chamber, and the heater is arranged, and the evaporator is arranged in an air passage communicating with the inside of the storage chamber through an air outlet, and the compressor and the condenser are arranged in the machine chamber. An evaporator fan, which is provided on a shelf on which the storage in the storage chamber is placed and is arranged in the air passage to generate an air flow passing through the evaporator, and an evaporator fan which is arranged in the machine chamber and passes through the condenser. Further provided with a condenser fan for generating an air flow to be generated, the control device operates the compressor in a state where the flow of the refrigerant is blocked by the blocking means after the heat retention by the heater is started. The refrigerant is collected by the machine room side of the refrigerant circuit, and the evaporator fan is stopped when the heater keeps the temperature warm.

The showcase according to the present invention is for keeping a refrigerant circuit in which a compressor, a condenser, an expansion valve, and an evaporator are connected in order by a refrigerant pipe filled with a refrigerant, and a storage in an open storage chamber. Heater, a blocking means provided in the refrigerant pipe between the condenser and the evaporator and capable of blocking the flow of the refrigerant, and a control device for controlling the compressor, the heater and the blocking means. , The refrigerant pipe provided in the refrigerant pipe between the evaporator and the compressor, which allows the flow of the refrigerant from the evaporator to the compressor, and allows the flow of the refrigerant from the compressor to the evaporator. The evaporator is provided with a check valve for prohibiting circulation, the evaporator is arranged in an air passage communicating with the inside of the storage chamber through an outlet, and the compressor and the condenser are arranged in the machine chamber. The heater is provided on a shelf on which the storage in the storage chamber is placed, is arranged in the air passage, and is arranged in the machine chamber with an evaporator fan that generates an air flow passing through the evaporator. a condenser fan for generating an air flow through the condenser, further wherein the controller stops the compressor in a state of being blocked the flow of the refrigerant by the pre-Symbol blocking means, and, be to operate the evaporator fan and the condenser fan in a state of performing heat keeping by the heater, rows that Align the recovery operation for recovering the refrigerant in the machine chamber side of the refrigerant circuit, the evaporator fan , It is stopped at the time of heat retention by the heater after the recovery operation.

Claims (12)

A refrigerant circuit in which a compressor, a condenser, an expansion valve, and an evaporator are connected in order by a refrigerant pipe filled with a refrigerant.
A heater to keep the storage in the storage room warm,
A blocking means provided in the refrigerant pipe between the condenser and the evaporator and capable of blocking the flow of the refrigerant.
The compressor, the heater, and a control device for controlling the blocking means are provided.
The evaporator is placed in an air passage that communicates with the inside of the storage chamber through an outlet.
The compressor and the condenser are arranged in the machine chamber.
Before starting the heat retention by the heater, the control device operates the compressor in a state where the flow of the refrigerant is blocked by the blocking means to recover the refrigerant to the machine room side of the refrigerant circuit. A showcase in which heat retention by the heater is started after the recovery operation is performed. A refrigerant circuit in which a compressor, a condenser, an expansion valve, and an evaporator are connected in order by a refrigerant pipe filled with a refrigerant.
A heater to keep the storage in the storage room warm,
A blocking means provided in the refrigerant pipe between the condenser and the evaporator and capable of blocking the flow of the refrigerant.
The compressor, the heater, and a control device for controlling the blocking means are provided.
The evaporator is placed in an air passage that communicates with the inside of the storage chamber through an outlet.
The compressor and the condenser are arranged in the machine chamber.
Before starting the heat retention by the heater, the control device operates the compressor in a state where the flow of the refrigerant is blocked by the blocking means to recover the refrigerant to the machine room side of the refrigerant circuit. A showcase in which a recovery operation is started and heat retention by the heater is started during the recovery operation. A refrigerant circuit in which a compressor, a condenser, an expansion valve, and an evaporator are connected in order by a refrigerant pipe filled with a refrigerant.
A heater to keep the storage in the storage room warm,
A blocking means provided in the refrigerant pipe between the condenser and the evaporator and capable of blocking the flow of the refrigerant.
The compressor, the heater, and a control device for controlling the blocking means are provided.
The evaporator is placed in an air passage that communicates with the inside of the storage chamber through an outlet.
The compressor and the condenser are arranged in the machine chamber.
After starting the heat retention by the heater, the control device operates the compressor in a state where the flow of the refrigerant is blocked by the blocking means to recover the refrigerant to the machine room side of the refrigerant circuit. Showcase for recovery operation. The showcase according to any one of claims 1 to 3, wherein the expansion valve also serves as the blocking means. Provided in the refrigerant pipe between the evaporator and the compressor, the flow of the refrigerant from the evaporator to the compressor is permitted, and the flow of the refrigerant from the compressor to the evaporator is permitted. The showcase according to any one of claims 1 to 4, further comprising a check valve for prohibiting. A pressure sensor provided in the refrigerant pipe between the evaporator and the check valve to detect the pressure of the refrigerant is further provided.
The control device ends the recovery operation when the pressure of the refrigerant in the refrigerant pipe between the evaporator and the check valve becomes equal to or lower than a preset reference pressure after the start of the recovery operation. The showcase according to claim 5. When the normal operation is restarted after the recovery operation, the control device performs the normal operation when the pressure of the refrigerant in the refrigerant pipe between the evaporator and the check valve is larger than the reference pressure. The showcase according to claim 6, which prohibits the resumption of operation. The showcase according to any one of claims 1 to 5, wherein the control device ends the recovery operation when a preset reference time has elapsed since the recovery operation was started. Further equipped with a temperature sensor for detecting the temperature of the condenser,
The control device according to any one of claims 1 to 5, wherein the control device terminates the recovery operation when the temperature of the condenser becomes equal to or lower than a preset reference temperature after the start of the recovery operation. Showcase. An evaporator fan that is placed in the air passage and generates an air flow that passes through the evaporator.
Further equipped with a condenser fan, which is arranged in the machine chamber and generates an air flow through the condenser.
The showcase according to any one of claims 1 to 9, wherein the control device operates one or both of the evaporator fan and the condenser fan during the recovery operation. The showcase according to claim 10, wherein the control device operates the condenser fan at a rotation speed higher than that during the normal operation during the recovery operation. The storage room and the machine room are formed in one housing.
The storage chamber is opened at the front of the housing and
The showcase according to any one of claims 1 to 11, wherein each of the air supply port and the exhaust port of the machine room is arranged on any one of the left side surface, the right side surface, and the back surface of the housing.

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