WO2021111560A1

WO2021111560A1 - Refrigeration cycle device

Info

Publication number: WO2021111560A1
Application number: PCT/JP2019/047500
Authority: WO
Inventors: 智隆石川; 野本　宗
Original assignee: 三菱電機株式会社
Priority date: 2019-12-04
Filing date: 2019-12-04
Publication date: 2021-06-10
Also published as: JPWO2021111560A1; JP7304965B2

Abstract

This refrigeration cycle device (1) comprises: a plurality of evaporators (51, 52); at least one image-capturing device (61, 62) for capturing images of the plurality of evaporators (51, 52); and a control device (100) which executes, on the basis of the images captured by said at least one image-capturing device (61, 62), a defrosting operation of an evaporator, in which the frosting amount exceeds a determination value, among the plurality of evaporators (51, 52). Preferably, the control device (100) is configured to perform a defrosting operation of one evaporator among the plurality of evaporators (51, 52). The control device (100) determines the execution order of the defrosting operation of the plurality of evaporators, on the basis of the captured images.

Description

Refrigeration cycle equipment

This disclosure relates to a refrigeration cycle device.

It is known that refrigeration cycle equipment may require defrosting operation. For example, in an air conditioner, since frost is formed on the outdoor heat exchanger during the heating operation to block the ventilation passage of the fins, the frosted state is periodically determined, and the defrosting operation is performed if necessary.

International Publication No. 2018/096608 (Patent Document 1) discloses an air conditioning system having an air conditioning state supplementing device that supplements information on the appearance of the air conditioning device during operation. The air conditioner has a control device that controls the operation of the outdoor unit based on the operation state information supplemented by the air conditioning state supplement device.

International Publication No. 2018/096608

In International Publication No. 2018/096608 (Patent Document 1), the operating state information supplemented by the air conditioning state supplement device is also used for determining defrosting.

However, the refrigeration cycle device configuration may have multiple evaporators. If the states of the plurality of evaporators are both states requiring defrosting, the defrosting operation may be executed for the plurality of evaporators at the same time. In such a case, it causes a significant decrease in refrigerating capacity.

An object of the present disclosure is to indicate a refrigeration cycle device in which an appropriate defrosting operation is performed in a refrigeration cycle device having a plurality of evaporators.

This disclosure relates to a refrigeration cycle device. The refrigeration cycle device is based on a plurality of evaporators, at least one image pickup device for photographing the plurality of evaporators, and an image taken by the at least one image pickup device, and the amount of frost formed among the plurality of evaporators is determined. It is equipped with a control device that executes defrosting operation of the evaporator that exceeds the determination value.

According to the refrigeration cycle apparatus of the present disclosure, since the amount of frost formation can be accurately determined, the timing of starting and stopping the defrosting operation can be appropriately determined.

FIG. 5 is an overall configuration diagram of a refrigeration cycle device according to the first embodiment. It is a figure for demonstrating an example of the positional relationship between an evaporator and an image pickup apparatus. It is a figure for demonstrating the calculation of the blockage rate. It is a flowchart for demonstrating the determination of the defrosting operation start for a plurality of evaporators. It is a flowchart which shows the detail of the defrosting process A executed in step S4 of FIG. It is a flowchart which shows the detail of the defrosting process B executed in step S5 of FIG. It is a flowchart which shows the detail of the defrosting process C executed in step S6 of FIG. It is a flowchart which shows the detail of the defrosting process D executed in step S8 of FIG. It is a conceptual diagram in the case of monitoring a plurality of evaporators by one image pickup apparatus. It is a figure which shows the 1st example which monitors a plurality of evaporators by one image pickup apparatus. It is a figure which shows the 2nd example which monitors a plurality of evaporators by one image pickup apparatus. It is a figure which shows the 3rd example which monitors a plurality of evaporators by one image pickup apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Hereinafter, a plurality of embodiments will be described, but it is planned from the beginning of the application that the configurations described in the respective embodiments are appropriately combined. The same or corresponding parts in the figure are designated by the same reference numerals.

Embodiment 1.
FIG. 1 is an overall configuration diagram of a refrigeration cycle device according to the first embodiment. With reference to FIG. 1, the refrigeration cycle apparatus 1 includes a compressor 10, a condenser 20, an expansion valve 30, a plurality of

solenoid valves

41, 42, a plurality of

evaporators

51, 52, and an

image pickup apparatus

61, 62,

heaters

71 and 72 for defrosting, and a control device 100 are provided.

For example, the freezing cycle device 1 is used as a refrigerator for cooling a freezing warehouse. In this case, the cold heat source unit including the compressor 10 and the condenser 20 is installed outdoors, and the load device including the

evaporators

51 and 52 is installed in the freezer warehouse.

The high-temperature and high-pressure gas refrigerant discharged from the compressor 10 is sent to the condenser 20 to condense and change into a liquid refrigerant. This liquid refrigerant adiabatically expands at the expansion valve 30 to become a two-phase refrigerant, and is distributed to the

evaporators

51 and 52 via the

solenoid valves

41 and 42. In each of the

evaporators

51 and 52, the two-phase refrigerant evaporates to become a gas refrigerant, and the gas refrigerant merges again and is sucked into the compressor 10.

The

evaporators

51 and 52 are configured to exchange heat between the refrigerant and the air in the refrigerating warehouse by blowing air from a fan (not shown). The condenser 20 is configured to exchange heat between the refrigerant and the air outside the refrigerating warehouse. Therefore, the heat inside the freezer warehouse is discharged to the outside of the freezer warehouse, and the inside of the freezer warehouse is cooled.

The compressor 10 is configured so that the operating frequency can be changed by a control signal received from the control device 100. The output of the compressor 10 is adjusted by changing the operating frequency of the compressor 10.

The control device 100 includes a CPU (Central Processing Unit) 101, a memory 102, an input / output buffer (not shown), and the like, and controls each device in the refrigeration cycle device. Note that this control is not limited to processing by software, but can also be processed by dedicated hardware (electronic circuit).

The

solenoid valves

41 and 42 are configured to be able to block the flow path that sends the refrigerant to the

evaporators

51 and 52. The

solenoid valves

41 and 42 may be replaced with electronic expansion valves, and the expansion valve 30 may be omitted.

The

image pickup devices

61 and 62 are, for example, digital cameras that capture the image data of the

evaporators

51 and 52, respectively. The control device 100 is configured to detect the amount of frost on the

evaporators

51 and 52 from the image data obtained by the

image pickup devices

61 and 62, and determine the necessity and priority of the defrosting operation. The image data obtained by the

image pickup devices

61 and 62 may be color or black and white.

FIG. 2 is a diagram for explaining an example of the positional relationship between the evaporator and the imaging device. As an example, the evaporator 51 and the image pickup device 61 will be described, but the positional relationship is the same for the evaporator 52 and the image pickup device 62. Moreover, the positional relationship is the same when more evaporators are provided.

The image pickup device 61 captures an image of a representative portion of the evaporator 51. The control device 100 regards the whitened portion in the representative image as frost formation. The whitened frost formation can be detected even in a black-and-white image.

As shown in FIG. 2, the representative portion of the evaporator 51 photographed by the control device 100 is the fin front edge portion on the air suction side. This portion is the portion of the evaporator 51 where frost is most likely to form.

The control device 100 starts the defrosting operation when a certain area ratio (for example, 50%) or more is whitened (frosted) in the image of the representative portion. Then, after the defrosting operation is started, the control device 100 ends the defrosting operation when the frosted portion of the image becomes a certain area ratio (for example, 10%) or less.

The blockage rate may be calculated to determine the necessity of defrosting. FIG. 3 is a diagram for explaining the calculation of the blockage rate. If the evaporator 51 is a plate fin tube type, the control device 100 detects the blockage rate between the fins FF due to frost formation, and if the blockage rate exceeds a certain value (for example, 50%), the defrosting operation is performed. Is started, and if the blockage rate becomes equal to or less than a certain value (for example, 10%) during the defrosting operation, the defrosting operation is terminated.

Here, the blockage rate is indicated by the ratio of the height of frost formed (H1 + H2) to the fin pitch FP FP / (H1 + H2) × 100 (%). Further, in the defrosting operation to be executed, the solenoid valve 41 is shut off and the frost attached to the fins of the evaporator 51 is melted by heating by the heater 71. If the refrigeration cycle device is an air conditioner capable of heating and cooling with a four-way valve, the evaporator may be switched to a condenser to defrost hot gas by dissipating heat from the refrigerant.

Here, the control device 100 identifies the evaporator that requires the defrosting operation, and starts the defrosting operation. At that time, if at least one evaporator is defrosting, the other evaporators are not defrosted. Therefore, when it is determined that the defrosting operation is necessary for a plurality of evaporators, the control device 100 schedules the defrosting operation so that the defrosting operation is sequentially performed from the one having the largest amount of frost formation.

The defrosting operation in this case is performed by shutting off the solenoid valve upstream of the evaporator to be defrosted and heating the surface of the evaporator with a heater.

FIG. 4 is a flowchart for explaining the determination of starting the defrosting operation for a plurality of evaporators. With reference to FIGS. 1 and 4, first, in step S1, the control device 100 determines whether or not defrosting is necessary in the evaporator 51. Subsequently, in step S2 or step S7, the evaporator 52 determines whether or not defrosting is necessary. In the above processing, defrosting is performed when the portion (for example, white portion) indicating frost formation of the image data obtained from the

image pickup devices

61 and 62 is a certain percentage (for example, 50%) or more of the area of the representative image. Judged necessary.

When it is determined that defrosting is necessary in both the evaporator 51 and the evaporator 52 (YES in S1 and YES in S2), in step S3, the frost formation amount M (51) of the evaporator 51 and the arrival of the evaporator 52 The amount of frost M (52) is compared. If M (51)> M52 (YES in S3), the defrosting process A is executed in step S4.

FIG. 5 is a flowchart showing details of the defrosting process A executed in step S4 of FIG. With reference to FIG. 5, in step S11, the control device 100 starts the defrosting operation of the evaporator 51. In the defrosting operation of the evaporator 51, the control device 100 closes the solenoid valve 41, stops the fan of the evaporator 51, and heats the frosted portion of the evaporator 51 by the heater 71. By doing so, the inside of the freezer warehouse is defrosted from the evaporator 51 while the cooling by the evaporator 52 is continued. At this time, since the fan of the evaporator 51 is stopped, it is possible to prevent the heat of the heater 71 from diffusing into the refrigerator and raising the temperature inside the refrigerator.

When the temperature inside the refrigerator is around 5 ° C, on the contrary, without using a heater, the refrigerant is shut off and the air inside the refrigerator is blown to the evaporator by a fan to melt the frost. You may perform the operation.

Subsequently, in step S12, the control device 100 determines whether or not the defrosting of the evaporator 51 is completed. As described above, when the area of the frosted portion decreases to a certain ratio (for example, 10%) after the start of defrosting, it can be determined that the defrosting is completed. If the defrosting operation time is too long, the temperature inside the refrigerator rises and wasteful power is consumed by the heater. On the contrary, if the defrosting operation time is too short, the operation is continued with the heat exchange efficiency of the evaporator being poor. As shown in the present embodiment, by determining the end of the defrosting operation while observing the actual frost formation state, the defrosting operation is not simply terminated when the defrosting operation time reaches a certain time. Defrosting can be stopped at just the right time.

If the defrosting of the evaporator 51 is not completed (NO in S12), the control device 100 returns the process to step S11 and continues the defrosting operation of the evaporator 51. On the other hand, when the defrosting of the evaporator 51 is completed (YES in S12), the control device 100 proceeds to the process in step S13.

In step S13, the control device 100 starts the defrosting operation of the evaporator 52. In the defrosting operation of the evaporator 52, the control device 100 closes the solenoid valve 42, stops the fan of the evaporator 52, and heats the frosted portion of the evaporator 52 by the heater 72.

Subsequently, in step S14, the control device 100 determines whether or not the defrosting of the evaporator 52 is completed. As described above, when the area of the frosted portion decreases to a certain ratio (for example, 10%) after the start of defrosting, it can be determined that the defrosting is completed.

If the defrosting of the evaporator 52 is not completed (NO in S14), the control device 100 returns the process to step S13 and continues the defrosting operation of the evaporator 52. On the other hand, when the defrosting of the evaporator 52 is completed (YES in S14), the control device 100 ends the defrosting process A.

Returning to FIG. 4 again, when M (51)> M52 is not satisfied (NO in S3), the defrosting process B is executed in step S5.

FIG. 6 is a flowchart showing details of the defrosting process B executed in step S5 of FIG. With reference to FIG. 6, in step S21, the control device 100 starts the defrosting operation of the evaporator 52. In the defrosting operation of the evaporator 52, the control device 100 closes the solenoid valve 42, stops the fan of the evaporator 52, and heats the frosted portion of the evaporator 52 by the heater 72. By doing so, the inside of the freezer warehouse is defrosted by the evaporator 52 while the cooling by the evaporator 51 is continued. At this time, since the fan of the evaporator 52 is stopped, it is possible to prevent the heat of the heater 72 from diffusing into the refrigerator and raising the temperature inside the refrigerator.

Subsequently, in step S22, the control device 100 determines whether or not the defrosting of the evaporator 52 is completed. The determination of the completion of defrosting can be determined when the area of the frosted portion decreases to a certain ratio (for example, 10%) after the start of defrosting as described above.

If the defrosting of the evaporator 52 is not completed (NO in S22), the control device 100 returns the process to step S21 and continues the defrosting operation of the evaporator 52. On the other hand, when the defrosting of the evaporator 52 is completed (YES in S22), the control device 100 proceeds to the process in step S23.

In step S23, the control device 100 starts the defrosting operation of the evaporator 51. In the defrosting operation of the evaporator 51, the control device 100 closes the solenoid valve 41, stops the fan of the evaporator 51, and heats the frosted portion of the evaporator 51 by the heater 71.

Subsequently, in step S24, the control device 100 determines whether or not the defrosting of the evaporator 51 is completed. As described above, when the area of the frosted portion decreases to a certain ratio (for example, 10%) after the start of defrosting, it can be determined that the defrosting is completed.

If the defrosting of the evaporator 51 is not completed (NO in S24), the control device 100 returns the process to step S23 and continues the defrosting operation of the evaporator 51. On the other hand, when the defrosting of the evaporator 51 is completed (YES in S24), the control device 100 ends the defrosting process B.

Returning to FIG. 4 again, when it is determined that the evaporator 51 needs to be defrosted and the evaporator 52 does not need to be defrosted (YES in S1 and NO in S2), the defrosting process C is executed in step S6. Will be done.

FIG. 7 is a flowchart showing details of the defrosting process C executed in step S6 of FIG. With reference to FIG. 7, in step S31, the control device 100 starts the defrosting operation of the evaporator 51. In the defrosting operation of the evaporator 51, the control device 100 closes the solenoid valve 41, stops the fan of the evaporator 51, and heats the frosted portion of the evaporator 51 by the heater 71. By doing so, the inside of the freezer warehouse is defrosted from the evaporator 51 while the cooling by the evaporator 52 is continued. At this time, since the fan of the evaporator 51 is stopped, it is possible to prevent the heat of the heater 71 from diffusing into the refrigerator and raising the temperature inside the refrigerator.

Subsequently, in step S32, the control device 100 determines whether or not the defrosting of the evaporator 51 is completed. The determination of the completion of defrosting can be determined when the area of the frosted portion decreases to a certain ratio (for example, 10%) after the start of defrosting as described above.

If the defrosting of the evaporator 51 is not completed (NO in S32), the control device 100 returns the process to step S31 and continues the defrosting operation of the evaporator 51. On the other hand, when the defrosting of the evaporator 51 is completed (YES in S32), the control device 100 ends the defrosting process C.

Returning to FIG. 4 again, when it is determined that defrosting is not necessary in the evaporator 51 and defrosting is necessary in the evaporator 52 (NO in S1 and YES in S7), the defrosting process D is executed in step S8. Will be done.

FIG. 8 is a flowchart showing details of the defrosting process D executed in step S8 of FIG. With reference to FIG. 8, in step S41, the control device 100 starts the defrosting operation of the evaporator 52. In the defrosting operation of the evaporator 52, the control device 100 closes the solenoid valve 42, stops the fan of the evaporator 52, and heats the frosted portion of the evaporator 52 by the heater 72. By doing so, the inside of the freezer warehouse is defrosted by the evaporator 52 while the cooling by the evaporator 51 is continued. At this time, since the fan of the evaporator 52 is stopped, it is possible to prevent the heat of the heater 72 from diffusing into the refrigerator and raising the temperature inside the refrigerator.

Subsequently, in step S42, the control device 100 determines whether or not the defrosting of the evaporator 52 is completed. As described above, when the area of the frosted portion decreases to a certain ratio (for example, 10%) after the start of defrosting, it can be determined that the defrosting is completed.

If the defrosting of the evaporator 52 is not completed (NO in S42), the control device 100 returns the process to step S41 and continues the defrosting operation of the evaporator 52. On the other hand, when the defrosting of the evaporator 52 is completed (YES in S42), the control device 100 ends the defrosting process D.

In the refrigeration cycle device 1 of the first embodiment described above, since the amount of frost formation is detected by an image, the necessity of defrosting can be determined with high accuracy, and unnecessary defrosting operation can be reliably prevented.

In addition, since the defrosting operation time can be minimized, it is possible to prevent a decrease in the heating capacity of the air conditioner and a decrease in the refrigerating capacity of the freezer warehouse due to the defrosting operation, and an energy saving effect can be obtained.

Furthermore, if the image is black and white, the camera cost can be reduced.
Embodiment 2.
In the first embodiment, the same number of image pickup devices are provided for the plurality of evaporators to monitor the frost formation state. However, even when a plurality of evaporators are installed, it is possible to reduce the number of image pickup devices.

FIG. 9 is a conceptual diagram in the case of monitoring a plurality of evaporators with one imaging device. As shown in FIG. 9, the refrigeration cycle device 201 includes an image pickup device 260 configured so that a plurality of evaporators 51 to 54 can be monitored. Although FIG. 1 shows an example in which the number of

evaporators

51 and 52 is two, FIG. 9 shows a case where the number of evaporators 51 to 54 is four. The number of evaporators may be increased or decreased depending on the size of the freezer warehouse. Since the circulation of the refrigerant is the same as that in FIG. 1, the description will not be repeated here.

FIG. 10 is a diagram showing a first example of monitoring a plurality of evaporators with one imaging device. In the first example shown in FIG. 10, the distance L between the image pickup device 260 and the

evaporators

51 and 52 is determined so that both the

evaporators

51 and 52 are within the imaging range of the image pickup device 260. In this case, it is necessary not to place a shield between the

evaporators

51 and 52 and the image pickup apparatus 260. Further, it is preferable that the

evaporators

51 and 52 are arranged so that the surface on the wind suction side described in FIG. 2 faces the image pickup apparatus 260.

FIG. 11 is a diagram showing a second example of monitoring a plurality of evaporators with one imaging device. In FIG. 11, a mirror M1 that reflects the frosted surface of the evaporator 51 and a mirror M2 that reflects the frosted surface of the evaporator 52 are used. By using a mirror, the degree of freedom of arrangement of the

evaporators

51 and 52 and the imaging device 260 in the refrigerator is increased.

FIG. 12 is a diagram showing a third example of monitoring a plurality of evaporators with one imaging device. In FIG. 12, one imaging device 260 is moved to sequentially photograph the frosted surfaces of the evaporators 51 to 54. In FIG. 12, a flying object such as a drone 300 is used for moving, but the method of moving is not limited to this. For example, a rail may be arranged on the ceiling or the like so that the image pickup apparatus 260 may be moved along the rail. Further, even when the image pickup device 260 is fixed in one place, the mirror shown in FIG. 11 can be rotated so that the frosted surfaces of the evaporators 51 to 54 are sequentially included in the image pickup device 260 shooting range. You can do it.

In addition, a device identification code (bar code, QR code (registered trademark), etc.) for identifying the evaporator is placed in each evaporator so as to be within the shooting range, and the shot image is processed to identify the evaporator. You may.

Also in the second embodiment, by performing the same treatment as in the first embodiment, the defrosting operation of each evaporator can be scheduled based on the amount of frost formation, and the occurrence of simultaneous defrosting can be prevented.

It is also possible to manage multiple evaporators at the same time by installing an imaging device in a freezer warehouse or the like. Therefore, in the second embodiment, the number of image pickup devices can be reduced as compared with the first embodiment. In addition, if the device identification code is read, the frosted evaporator can be identified only by the image, which makes it easier to manage the image data.

Finally, the present embodiment will be summarized with reference to the drawings again.
The present disclosure relates to a refrigeration cycle device. The refrigeration cycle device 1 shown in FIG. 1 and the refrigeration cycle device 201 shown in FIG. 9 include a plurality of

evaporators

51, 52, and at least one

imaging device

61, 62, 260 for photographing the plurality of

evaporators

51, 52. A control device 100 that executes a defrosting operation of an evaporator in which the amount of frost formation exceeds a determination value among a plurality of

evaporators

51 and 52, based on images taken by at least one

image pickup device

61, 62, 260. And.

Preferably, as shown in FIGS. 4 to 8, when there are a plurality of evaporators to be defrosted, the control device 100 determines the execution order of the defrosting operations of the plurality of evaporators based on the image. ..

By controlling in this way, even if frost is formed on a plurality of evaporators at the same time, the defrosting operation is not executed for the plurality of evaporators at the same time, so that a significant increase in the internal temperature can be prevented.

Preferably, as shown in FIGS. 10 and 11, at least one imaging device 260 is configured to capture a plurality of evaporators on one captured image.

With such a configuration, the number of image pickup devices installed can be reduced, so that the manufacturing cost of the refrigeration cycle device can be reduced.

Preferably, as shown in FIG. 12, at least one imaging device 260 is one. The refrigeration cycle device 201 further includes a transport device such as a drone 300 that sequentially transports the image pickup device 260 to a plurality of imaging positions capable of capturing images of the plurality of evaporators 51 to 54, respectively. The transport device is not limited to the drone 300, and may be a mobile trolley or the like that travels along the rails of the ceiling, floor, or wall.

The embodiments disclosed this time should be considered to be exemplary in all respects and not restrictive. The scope of the present invention is shown by the claims rather than the description of the embodiments described above, and is intended to include all modifications within the meaning and scope equivalent to the claims.

1,201 Refrigeration cycle device, 10 compressor, 20 condenser, 30 expansion valve, 41,42 solenoid valve, 51,52,54 evaporator, 61,62,260 imaging device, 71,72 heater, 100 control device, 101 CPU, 102 memory, 300 drone, F fin, M1, M2 mirror.

Claims

With multiple evaporators,
At least one image pickup device for photographing the plurality of evaporators, and
A refrigeration cycle device including a control device for executing a defrosting operation of an evaporator in which the amount of frost formation among the plurality of evaporators exceeds a determination value based on an image taken by the at least one imaging device. ..
The refrigeration cycle device according to claim 1, wherein the control device determines the execution order of the defrosting operation of the plurality of evaporators based on the image when there are a plurality of evaporators to be defrosted.
The refrigeration cycle device according to claim 1, wherein the at least one imaging device is configured to capture the plurality of evaporators on one captured image.
The at least one imaging device is one.
The refrigeration cycle device according to claim 1, further comprising a transport device for sequentially transporting the image pickup device to a plurality of shooting positions capable of capturing images of the plurality of evaporators.