JP7304965B2 - refrigeration cycle equipment - Google Patents

Description

The present disclosure relates to a refrigeration cycle device.

It is known that a refrigerating cycle device may require a defrosting operation. For example, in an air conditioner, frost builds up on the outdoor heat exchanger during heating operation, blocking the ventilation passages of the fins.

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

WO2018/096608

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

However, the configuration of the refrigeration cycle device may have multiple evaporators. If the states of a plurality of evaporators are states that both require defrosting, there is a possibility that the defrosting operation will be performed on the plurality of evaporators at the same time. In such a case, a significant decrease in refrigerating capacity is caused.

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

The present disclosure relates to a refrigeration cycle device. A refrigerating cycle apparatus includes: a plurality of evaporators; at least one imaging device that photographs the plurality of evaporators; and a control device for executing a defrosting operation of the evaporator exceeding the judgment value.

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

1 is an overall configuration diagram of a refrigeration cycle apparatus according to Embodiment 1. FIG. FIG. 4 is a diagram for explaining an example of a positional relationship between an evaporator and an imaging device; FIG. 4 is a diagram for explaining calculation of a blockage rate; FIG. 10 is a flowchart for explaining determination of defrosting operation start for a plurality of evaporators; FIG. FIG. 5 is a flow chart showing details of a defrosting process A executed in step S4 of FIG. 4; FIG. FIG. 5 is a flow chart showing details of a defrosting process B executed in step S5 of FIG. 4. FIG. FIG. 5 is a flow chart showing details of a defrosting process C executed in step S6 of FIG. 4; FIG. FIG. 5 is a flow chart showing details of a defrosting process D executed in step S8 of FIG. 4. FIG. FIG. 4 is a conceptual diagram of monitoring a plurality of evaporators with one imaging device; FIG. 4 is a diagram showing a first example of monitoring a plurality of evaporators with one imaging device; FIG. 10 is a diagram showing a second example of monitoring a plurality of evaporators with one imaging device; FIG. 11 is a diagram showing a third example of monitoring a plurality of evaporators with one imaging device;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. A plurality of embodiments will be described below, but appropriate combinations of the configurations described in the respective embodiments have been planned since the filing of the application. The same reference numerals are given to the same or corresponding parts in the drawings.

Embodiment 1.
FIG. 1 is an overall configuration diagram of a refrigeration cycle apparatus according to Embodiment 1. FIG. Referring to FIG. 1, refrigeration cycle apparatus 1 includes a compressor 10, a condenser 20, an expansion valve 30, a plurality of electromagnetic valves 41 and 42, a plurality of evaporators 51 and 52, an imaging device 61, 62 , heaters 71 and 72 for defrosting, and a control device 100 .

For example, the refrigeration cycle device 1 is used as a refrigerator that cools a freezer warehouse. In this case, a cold heat source unit including the compressor 10 and the condenser 20 is installed outdoors, and a load device including the evaporators 51 and 52 is installed inside the freezer warehouse.

The high-temperature and high-pressure gas refrigerant discharged from the compressor 10 is sent to the condenser 20 to be condensed and changed to a liquid refrigerant. This liquid refrigerant adiabatically expands in the expansion valve 30 to become a two-phase refrigerant, which is distributed to the evaporators 51 and 52 via the electromagnetic valves 41 and 42 . In each of the evaporators 51 and 52 , the two-phase refrigerant evaporates into gas refrigerant, and the gas refrigerant joins 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 freezer warehouse by blowing air from a fan (not shown). Condenser 20 is configured to exchange heat between the refrigerant and the air outside the freezer warehouse. Therefore, the heat inside the freezer is discharged to the outside of the freezer and the inside of the freezer is cooled.

Compressor 10 is configured to be able to change its operating frequency according to a control signal received from control device 100 . By changing the operating frequency of the compressor 10, the output of the compressor 10 is adjusted.

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

The electromagnetic valves 41 and 42 are configured so as to be able to cut off the flow path for sending the refrigerant to the evaporators 51 and 52 . Note that the electromagnetic valves 41 and 42 may be replaced with electronic expansion valves, and the expansion valve 30 may be omitted.

Imaging devices 61 and 62 are, for example, digital cameras that capture image data of evaporators 51 and 52, respectively. The control device 100 is configured to detect the amount of frost formed on the evaporators 51 and 52 from the image data obtained by the imaging devices 61 and 62, and determine the necessity and priority of the defrosting operation. The image data obtained by the imaging devices 61 and 62 may be in color, or may be in 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 imaging device 61 will be described, but the positional relationship of the evaporator 52 and the imaging device 62 is the same. The positional relationship is the same even when more evaporators are provided.

The imaging device 61 takes an image of a representative portion of the evaporator 51 . The control device 100 regards a whitened portion in the representative image as frost formation. Whitening frost formation can also be detected in black-and-white images.

A representative portion of the evaporator 51 photographed by the control device 100 is, as shown in FIG. 2, the fin leading edge portion on the air intake side. This portion is the most likely to frost in the evaporator 51 .

Control device 100 starts the defrosting operation when a certain area ratio (for example, 50%) or more of the image of the representative portion becomes white (frosts). Then, after starting the defrosting operation, the control device 100 ends the defrosting operation when the area ratio of the frosted portion of the image becomes equal to or less than a certain area ratio (for example, 10%).

It should be noted that the necessity of defrosting may be determined by calculating the blockage rate. FIG. 3 is a diagram for explaining the calculation of the clogging rate. If the evaporator 51 is of the 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 the defrosting operation is terminated when the clogging rate becomes equal to or less than a certain value (for example, 10%) during the defrosting operation.

Here, the blockage ratio is indicated by the ratio FP/(H1+H2)×100(%) of the frost height (H1+H2) with respect to the fin pitch FP. Also, in the defrosting operation that is executed, the electromagnetic valve 41 is shut off and the frost on 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 cooling and heating with a four-way valve, the evaporator may be switched to a condenser to defrost the hot gas by releasing heat from the refrigerant.

Here, the control device 100 identifies evaporators that require defrosting operation and starts defrosting operation. At that time, when at least one evaporator is defrosting, the defrosting operation is not performed in the other evaporators. 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 defrosting is performed sequentially from the evaporator with the larger frost amount.

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

FIG. 4 is a flow chart for explaining determination of defrosting operation start for a plurality of evaporators. 1 and 4, first, in step S1, control device 100 determines whether or not evaporator 51 needs defrosting. Subsequently, in step S2 or step S7, it is determined whether defrosting is necessary in the evaporator 52 or not. In the above process, when the portion (for example, white portion) indicating frost formation in the image data obtained from imaging devices 61 and 62 is a certain percentage (for example, 50%) or more of the area of the representative image, defrosting is performed. deemed necessary.

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

FIG. 5 is a flow chart showing details of the defrosting process A executed in step S4 of FIG. Referring to FIG. 5, control device 100 starts the defrosting operation of evaporator 51 in step S11. 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 with the heater 71 . By doing so, defrosting of the evaporator 51 is performed while cooling by the evaporator 52 is continued in the freezer warehouse. Since the fan of the evaporator 51 is stopped at this time, it is possible to prevent the heat of the heater 71 from diffusing into the inside of the refrigerator and increasing the temperature inside the refrigerator.

When the temperature inside the refrigerator is around 5°C, on the contrary, the heater is not used, the refrigerant is cut off, and the air inside the refrigerator is blown to the evaporator by the fan to melt the frost. You can execute driving.

Subsequently, in step S12, the control device 100 determines whether the defrosting of the evaporator 51 has been completed. As described above, it can be determined that defrosting is completed when the area of the frosted portion has decreased to a certain percentage (eg, 10%) after defrosting is started. If the defrosting operation time is too long, the inside temperature rises and power is wasted by the heater. Conversely, if the defrosting operation time is too short, the operation will continue while the heat exchange efficiency of the evaporator is poor. As shown in the present embodiment, by judging whether to end the defrosting operation while observing the actual frost formation state, rather than simply ending the defrosting operation when the defrosting operation time reaches a certain time, Defrosting can be stopped at just the right moment.

If the defrosting of the evaporator 51 has not been 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, if the defrosting of evaporator 51 has been completed (YES in S12), control device 100 advances the process to step S13.

At step S<b>13 , 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 with the heater 72 .

Subsequently, in step S14, control device 100 determines whether defrosting of evaporator 52 has been completed. As described above, it can be determined that defrosting is completed when the area of the frosted portion has decreased to a certain percentage (eg, 10%) after defrosting is started.

If the defrosting of the evaporator 52 has not been 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, if the defrosting of the evaporator 52 has been completed (YES in S14), the control device 100 terminates the defrosting process A.

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

FIG. 6 is a flow chart showing details of the defrosting process B executed in step S5 of FIG. Referring to FIG. 6, control device 100 starts the defrosting operation of evaporator 52 in step S21. 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 with the heater 72 . By doing so, defrosting of the evaporator 52 is performed while cooling by the evaporator 51 is continued in the freezer warehouse. Since the fan of the evaporator 52 is stopped at this time, it is possible to prevent the heat from the heater 72 from diffusing into the inside of the refrigerator and increasing the temperature inside the refrigerator.

Subsequently, in step S22, control device 100 determines whether defrosting of evaporator 52 has been completed. Defrosting completion can be determined when the area of the frosted portion has decreased to a certain percentage (for example, 10%) after defrosting is started 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, if the defrosting of evaporator 52 has been completed (YES in S22), control device 100 proceeds to step S23.

At step S<b>23 , 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 with the heater 71 .

Subsequently, in step S24, the control device 100 determines whether defrosting of the evaporator 51 is completed. As described above, it can be determined that defrosting is complete when the area of the frosted portion has decreased to a certain percentage (for example, 10%) after defrosting is started.

If the defrosting of the evaporator 51 has not been 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, if the defrosting of the evaporator 51 has been completed (YES in S24), the control device 100 terminates the defrosting process B.

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

FIG. 7 is a flow chart showing details of the defrosting process C executed in step S6 of FIG. Referring to FIG. 7, control device 100 starts the defrosting operation of evaporator 51 in step S31. 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 with the heater 71 . By doing so, defrosting of the evaporator 51 is performed while cooling by the evaporator 52 is continued in the freezer warehouse. Since the fan of the evaporator 51 is stopped at this time, it is possible to prevent the heat of the heater 71 from diffusing into the inside of the refrigerator and increasing the temperature inside the refrigerator.

Subsequently, in step S32, the control device 100 determines whether the defrosting of the evaporator 51 has been completed. Defrosting completion can be determined when the area of the frosted portion has decreased to a certain percentage (for example, 10%) after defrosting is started as described above.

If the defrosting of the evaporator 51 has not been 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, if the defrosting of the evaporator 51 has been completed (YES in S32), the control device 100 terminates the defrosting process C.

Returning to FIG. 4 again, when it is determined that defrosting is unnecessary in evaporator 51 and defrosting is necessary in evaporator 52 (NO in S1 and YES in S7), defrosting process D is executed in step S8. be done.

FIG. 8 is a flow chart showing details of the defrosting process D executed in step S8 of FIG. Referring to FIG. 8, control device 100 starts the defrosting operation of evaporator 52 in step S41. 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 with the heater 72 . By doing so, defrosting of the evaporator 52 is performed while cooling by the evaporator 51 is continued in the freezer warehouse. Since the fan of the evaporator 52 is stopped at this time, it is possible to prevent the heat from the heater 72 from diffusing into the inside of the refrigerator and increasing the temperature inside the refrigerator.

Subsequently, in step S42, control device 100 determines whether defrosting of evaporator 52 has been completed. As described above, it can be determined that defrosting is completed when the area of the frosted portion has decreased to a certain percentage (eg, 10%) after defrosting is started.

If the defrosting of the evaporator 52 has not been 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, if the defrosting of the evaporator 52 has been completed (YES in S42), the control device 100 terminates the defrosting process D.

In the refrigerating cycle apparatus 1 of Embodiment 1 described above, since the amount of frost formed is detected using an image, it is possible to determine with high accuracy whether or not defrosting is necessary, and to reliably prevent unnecessary defrosting operations.

In addition, since the defrosting operation time can be minimized, it is possible to prevent the deterioration of the heating capacity of the air conditioner and the cooling capacity of the freezer warehouse due to the defrosting operation, and to obtain an energy saving effect.

Furthermore, if the image is black and white, the cost of the camera can be reduced.
Embodiment 2.
In Embodiment 1, the same number of imaging devices are provided for a plurality of evaporators to monitor the frost formation state. However, even when installing a plurality of evaporators, it is possible to reduce the number of imaging devices.

FIG. 9 is a conceptual diagram of monitoring a plurality of evaporators with one imaging device. As shown in FIG. 9, the refrigerating cycle apparatus 201 includes an imaging device 260 configured to monitor the plurality of evaporators 51-54. Although FIG. 1 shows an example in which there are two evaporators 51 and 52, FIG. 9 shows a case in which there are four evaporators 51-54. The number of evaporators may be increased or decreased depending on the size of the freezer warehouse. Note that the circulation of the refrigerant and the like are the same as those in FIG. 1, and therefore 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 imaging device 260 and the evaporators 51 and 52 is determined so that both the evaporators 51 and 52 are within the shooting range of the imaging device 260 . In this case, it is necessary not to place a shield between the evaporators 51 and 52 and the imaging device 260 . Also, the evaporators 51 and 52 are preferably arranged so that the surfaces on the air intake side described in FIG.

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 for reflecting the frosted surface of the evaporator 51 and a mirror M2 for reflecting the frosted surface of the evaporator 52 are used. The use of mirrors increases the flexibility of placement of the evaporators 51, 52 and imaging device 260 within the cabinet.

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 51-54. In FIG. 12, a flying object such as the drone 300 is used for movement, but the movement method is not limited to this. For example, a rail may be placed on the ceiling or the like, and the imaging device 260 may be moved along the rail. Even if the imaging device 260 is fixed in one place, the mirror shown in FIG. You can do it.

In addition, a device identification code (bar code, QR code (registered trademark), etc.) for identifying the evaporator is placed on each evaporator so that it falls within the shooting range, and the captured image is processed to identify the evaporator. You may

Also in the second embodiment, by performing the same processing as in the first embodiment, it is possible to schedule the defrosting operation of each evaporator based on the amount of frost formation, thereby preventing simultaneous defrosting.

Also, if an imaging device is installed in a freezer warehouse or the like, it is possible to manage a plurality of evaporators at the same time. Therefore, in the second embodiment, it is possible to reduce the number of imaging apparatuses as compared with the first embodiment. Also, by reading the device identification code, the frosted evaporator can be identified only by the image, which facilitates management of the image data.

Finally, referring to the drawings again, the present embodiment will be summarized.
The present disclosure relates to a refrigeration cycle device. Refrigeration cycle apparatus 1 shown in FIG. 1 and refrigeration cycle apparatus 201 shown in FIG. A control device 100 for executing a defrosting operation of an evaporator out of the plurality of evaporators 51, 52 in which the amount of frost formation exceeds a determination value, based on images captured by at least one imaging device 61, 62, 260. and

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

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 operation of the plurality of evaporators based on the image. .

By controlling in this way, even if a plurality of evaporators are frosted at the same time, the defrosting operation is not performed for the plurality of evaporators at the same time, thereby preventing a significant increase in the internal temperature.

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

By adopting such a configuration, the number of installed imaging devices 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 apparatus 201 further includes a transportation device such as a drone 300 that sequentially transports the imaging device 260 to a plurality of imaging positions capable of imaging images of the plurality of evaporators 51 to 54, respectively. Note that the transport device is not limited to the drone 300, and may be a mobile trolley or the like that travels along rails on the ceiling, floor, or wall.

By adopting such a configuration, the number of installed imaging devices can be reduced, so that the manufacturing cost of the refrigeration cycle device can be reduced.

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

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

Claims (2)

a plurality of evaporators;
at least one imager for imaging the plurality of evaporators;
a control device for executing a defrosting operation of an evaporator among the plurality of evaporators whose amount of frost formation exceeds a judgment value, based on the image captured by the at least one imaging device;
The refrigeration cycle apparatus, wherein the at least one imaging device is configured to photograph the plurality of evaporators in one photographed image. The refrigeration cycle apparatus according to claim 1, wherein, when there are a plurality of evaporators to be defrosted, said control device determines the execution order of defrosting operation of said plurality of evaporators based on said image.

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