JPH10246558A - Operating method of showcase and controller thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the rise of an inside temperature by a method wherein the supply of refrigerant to all of coolers is stopped when predetermined defrosting operation is not effected even when a previously set time has been arrived. SOLUTION: When cooling operation is continued for a long period of time (S21 or S25) and the operation is not advanced into defrosting operation A (S22) or defrosting operation B (S26), the time of elapse from previous defrosting operation is judged that it has arrived at an elapse allowable time (S31 or S32). In this case, the supply of refrigerant to all of coolers is stopped and forced defrosting is effected (S33 or S34) whereby defrosting of all coolers is effected. According to this method, even when the cooling operation is continued for a long period of time due to some reason and much amount of frost or ice is adhered to the cooler, the frost or ice can be removed within a range of some degree of amount.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a showcase operating method and a control device, and more particularly, to a showcase operating method and a control device for a showcase in which a plurality of coolers are alternately defrosted. is there.

[0002]

2. Description of the Related Art As shown in FIG.
The showcase 1 provided with B suppresses temperature fluctuations in the showcase (inside the refrigerator) by alternately performing the defrosting operation of the coolers A and B, and performs efficient defrosting using the properties of the refrigerant. A frost operation can be performed, and the defrost operation is usually performed at a preset time interval.

[0003]

However, if the defrosting operation is not performed for a long time for some reason, that is, if the cooling operation is continued for a long time, the amount of frost on the cooler increases, The cooling capacity gradually decreases, and the inside of the refrigerator cannot be cooled to a predetermined temperature. In such a case,
In the past, measures were taken to stop the operation of the refrigerator artificially depending on the condition of the refrigerator temperature. In some cases had an adverse effect on the product being sold.

Therefore, the present invention can automatically defrost a cooler by a method different from a normal defrosting operation even when the defrosting operation has not been started for a long time, and can reduce the internal temperature of the refrigerator. An object of the present invention is to provide a method of operating a showcase and a control device for the showcase, which can prevent ascent.

[0005]

In order to achieve the above object, a method of operating a showcase according to the present invention comprises a plurality of coolers and alternately performs defrosting. The elapsed time from the time of the frost operation is measured, and when the predetermined time has not been performed even if the elapsed time reaches a preset time, the supply of the refrigerant to all the coolers is stopped. The defrosting of the cooler is performed by using

[0006] According to the above configuration, when the elapsed time from the previous defrosting operation reaches a preset time, for example, 6 hours, the supply of the refrigerant to all the coolers is stopped and the coolers are stopped. Since the defrosting is forcibly performed, the normal cooling operation is performed after the forcible defrosting is performed, so that an increase in the temperature in the refrigerator can be minimized.

Further, the showcase control device of the present invention includes a plurality of coolers, and the showcase control device which alternately performs the defrosting operation of each of the coolers, wherein the elapsed time since the previous defrosting operation is performed. Elapsed time measuring unit that measures the elapsed time setting unit that sets the permissible time elapsed since the previous defrosting operation, and compares the elapsed time of the elapsed time counting unit with the elapsed time allowed of the elapsed time setting unit. If the predetermined defrosting operation is not performed even if the elapsed time of the elapsed time timer reaches the elapsed allowable time of the elapsed time setting unit, the controller stops supplying the refrigerant to all the coolers. And a comparison operation unit for sending a signal for defrosting the cooler.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing a main part of a control device for a showcase of the present invention, FIG. 2 is a flowchart showing an example of a procedure in a first configuration of the method of the present invention, and FIG. 3 is a flowchart in a second configuration of the method of the present invention. It is a flowchart which shows an example of a procedure.

First, as shown in FIG. 1, the control device of the present invention is applied to a showcase having a plurality of, for example, two systems of coolers A and B, as in the showcase 1 shown in FIG. The control unit 11 includes a normal control unit (not shown), for example, a control unit that performs temperature control and defrost control.
An elapsed time timer 12 for measuring an elapsed time from the previous defrosting operation, an elapsed time setting unit 13 for setting an allowable elapsed time since the previous defrosting operation, and the elapsed time timer 12
When the elapsed time of the elapsed time counting unit 12 reaches the elapsed allowable time of the elapsed time setting unit 13 by comparing the elapsed time of the elapsed time with the elapsed allowable time of the elapsed time setting unit 13, the predetermined defrosting operation is not performed. In this case, the comparison operation unit 14 that sends a signal for defrosting all the coolers to the control unit 11 by stopping the supply of the refrigerant to all the coolers provided in the showcase, Power detection means 15 for detecting the state of
And an operation state storage unit 16 for storing an operation state at the time of power supply interruption based on a detection signal from the power supply detection means 15.

By forming the control device of the showcase in this manner, the defrosting operation is performed even if the elapsed time from the previous defrosting operation has reached the permissible time set in the elapsed time setting unit 13. If not, that is, if the cooling operation has been performed for a long time, the comparison operation unit 14
, The supply of the refrigerant to all the coolers is stopped and the forced defrosting operation (off-cycle defrosting) for defrosting all the coolers can be performed. As a result, the cooling capacity of the cooler can be restored, and the cooling operation does not continue for a long time in a state in which a large amount of frost has adhered and the cooling capacity has almost disappeared. Can be suppressed.

The permissible elapsed time set in the elapsed time setting section 13 is longer than the defrost timing in the normal operation state, and is set in consideration of the operating temperature of the showcase, the amount of frost on the cooler, and the like. What is necessary is just to make it normally, and should just be about 4 to 8 hours. In addition, this forced defrosting is usually performed by setting a time capable of sufficiently removing frost attached to the cooler by off-cycle defrosting for a predetermined time (for example,
30 minutes), but the temperature sensor detects the temperature of the cooler part and the cool air temperature in the cool air blowout part.
A method similar to the procedure for terminating a normal defrosting operation, such as a method of terminating when the detected temperature becomes equal to or higher than a predetermined temperature, can be used.

Further, the control device includes a power supply detecting means 1
5 and the operation state storage unit 16, the operation state storage unit 1 is provided when the power supply is shut down and the power supply is restored.
The operation can be resumed in the operation state at the time of power-off stored in 6. Therefore, when the power supply is cut off during the cooling operation, the operation is restarted from the cooling operation, so that there is no occurrence of cooling failure compared to, for example, the operation restarting from the pump-down operation. Similarly, if the power supply is interrupted for a short time during the defrosting operation, the operation is restarted from the defrosting operation when the power is restored, so that a sufficient defrosting operation can be performed, and the defrosting of the cooler can be performed. Defects can be prevented.

FIG. 2 shows an example of a flowchart for implementing the first configuration in the method of the present invention. First, the line from step 21 to step 28 shows the flow of the normal operation state. In the first step 21, a normal cooling operation using two systems of coolers is performed. At this time, the control unit 11
It outputs a temperature control output according to changes in the internal temperature etc. detected by various temperature sensors.

Next, in step 22, a defrosting operation A for defrosting one of the coolers is performed according to a preset defrosting start condition. The defrosting operation A is performed for a predetermined time or until the temperature of the cooler portion rises to a predetermined temperature by supplying the high-pressure refrigerant to the cooler that performs the defrosting operation.
Subsequently, after resetting the elapsed time measured by the elapsed time timer 12 in step 23, the refrigerant recovery operation (pump down operation) A in step 24 is performed, and the high-pressure refrigerant in the cooler is recovered. Preparation for the next cooling operation is performed.

When the defrosting of one of the coolers is completed as described above, the cooling operation by the two coolers is started again in step 25, and the same control as in step 21 is performed.
Next, in step 26, a defrosting operation B for defrosting the other cooler is performed. Subsequently, in step 27, the elapsed time of the elapsed time counting unit 12 is reset. The refrigerant recovery operation B is performed, and the process returns to step 21 which is the first operation state.

Then, by the steps 31 and 32 provided in parallel with the cooling operation in step 21 and the cooling operation in step 25, the elapsed time from the previous defrosting operation measured by the elapsed time timer 12 is calculated. The time and the elapsed allowable time set in the elapsed time setting unit 13 are compared with the comparison operation unit 1.
4 is compared. In the normal normal operation state, the elapsed time from the previous defrosting operation does not reach the set permissible time, so the process returns directly from step 31 or 32 to the cooling operation of step 21 or step 25, A predetermined cooling operation is performed.

On the other hand, step 21 or step 25
Is continued for a long time, and does not proceed to the defrosting operation A of step 22 or the defrosting operation B of step 26, in step 31 or step 32,
Since it is determined that the elapsed time from the previous defrosting operation has reached the permissible elapsed time, in this case, the process proceeds to the next step 33 or step 34 and the supply of the refrigerant to all the coolers is stopped. By performing forced defrosting, all the coolers are defrosted.

Thus, even if the cooling operation is continued for a long time for some reason and a large amount of frost or ice adheres to the cooler, it is possible to remove the frost or ice within a certain amount. It is possible to prevent the occurrence of cooling failure due to frosting or the like.

When the forced defrost in step 33 or 34 is completed, step 35 or 36
Then, the elapsed time of the elapsed time counting unit 12 is reset, the operation returns to the cooling operation in step 21 or 25, the operation is restarted, and the process returns to the loop for performing the normal operation procedure.

By operating in this manner, for example,
If the elapsed allowable time is set to 6 hours, even if the normal defrosting operation is not performed for some reason during the holiday,
Since it is possible to reliably defrost the cooler every time,
The temperature inside the refrigerator does not rise abnormally, and the freshness of the displayed product can be maintained.

FIG. 3 is a flowchart for explaining another function provided in the control device. Steps 21 to 28 in this flowchart are the same as those in the flowchart shown in FIG. 2. Step 21 is a cooling operation, step 22 is a defrosting operation A, step 24 is a refrigerant recovery operation A, and step 25 is a cooling operation again. ,
Step 26 is a defrosting operation B, and step 28 is a refrigerant recovery operation B, which is a loop during normal operation. Steps (23, 27) for resetting the elapsed time irrelevant to the description of this flowchart are omitted from the drawings and description.

In this flowchart, while the operation of steps 21 to 28 is being performed, the state of the power supply is constantly monitored by the power supply detecting means 15. When the power supply is in a normal state, the storage is always updated. The latest operation state is stored in the operation state storage unit 16. Then, when the power supply is artificially turned off due to maintenance or the like and the power supply is cut off due to a power failure, steps 21 to 2 are performed.
In any one of the operation states of 8, the process proceeds to step 41,
The operation state at the time of power shutdown is stored and held in the operation state storage unit 16.

When the power returns to a normal state due to power ON or recovery from a power failure, the power detection means 15 detects this in step 42, and in step 43 the power OFF or power failure stored in the operation state storage unit 16 causes the power failure. The operation state immediately before the power supply cutoff is determined, and the process returns to any one of the steps 21 to 28 to resume the operation in the operation state immediately before the power supply cutoff.

Thus, when the cooling operation is being performed, the state of the cooling operation (step 21 or step 2) is performed.
Since the operation is restarted in 5), a predetermined cooling operation can be performed without increasing the temperature in the refrigerator. In addition, when either of the defrosting operations A and B is being performed (step 22 or step 26), the defrosting operation is restarted.
After sufficiently performing the defrosting of the cooler, the process proceeds to the next refrigerant recovery operation (Step 24 or Step 28).

Therefore, when the power supply shuts down immediately after the start of the defrosting operations A and B, and when the power supply is recovered in a short time (restoration of the power failure), the predetermined defrosting operation can be continued. Thus, sufficient defrosting can be performed in the same manner as in the normal case. Accordingly, the refrigerant recovery operation is performed while the defrosting is insufficient, and the cooling operation is started. The cooling operation is prevented from being affected by the frost remaining in the cooler, and the predetermined cooling operation can be performed.

[0026]

As described above, according to the showcase operating method and the control device of the present invention, the cooling operation is continued for a long time without performing the predetermined defrosting operation due to the occurrence of some abnormality. Even in such a case, since all the coolers are forcibly defrosted at regular intervals, it is possible to prevent the occurrence of defective cooling due to abnormal frost formation on the coolers.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main part of a control device for a showcase of the present invention.

FIG. 2 is a flowchart showing an example of a procedure of the method of the present invention.

FIG. 3 is a flowchart illustrating another function of the control device.

FIG. 4 is a schematic sectional view of a showcase provided with two systems of coolers.

[Explanation of symbols]

 A, B cooler 1 showcase 11 control unit 12 elapsed time counting unit 13 elapsed time setting unit 14 comparison operation unit 15 power supply detection means 16 operation state storage unit

Claims (2)

[Claims] In a showcase operating method comprising a plurality of coolers and alternately performing defrosting, an elapsed time from a previous defrosting operation is measured, and the elapsed time reaches a preset time. Even if the predetermined defrosting operation has not been performed, the supply of the refrigerant to all the coolers is stopped to perform the defrosting of the coolers, whereby a showcase operating method is provided. 2. A control device for a showcase comprising a plurality of coolers and alternately performing a defrosting operation of each of the coolers, comprising: an elapsed time timer for measuring an elapsed time from a previous defrosting operation; The elapsed time setting unit that sets the permissible time since the defrosting operation of the defrosting operation, and the elapsed time of the elapsed time timer is compared by comparing the elapsed time of the elapsed time timer with the elapsed time of the elapsed time setting unit. When the predetermined defrosting operation is not performed even when the elapsed allowable time of the time setting unit is reached, a signal for performing defrosting of the coolers by stopping the supply of the refrigerant to all the coolers to the control unit. A control device for a showcase, comprising: a comparison operation unit that sends the data.