JPH0718637B2 - Defrost control device for cooling device - Google Patents

Description

The present invention relates to a defrost control device for a cooling device having a plurality of refrigeration units.

Conventional technology When the defrosting means is turned on after a lapse of a predetermined time from the start of the cooling operation, at the end of defrosting (the defrosting end detecting means is present)
As a refrigerator having defrosting control means for turning off
-210382 is available. With this technology,
A refrigerant circuit consisting of a radiator / cooler / flow passage opening / closing means interposed between the radiator and the cooler, a defrosting means of the cooler having a heater, and a defrosting termination time of the defrosting means A flow path opening / closing control means that closes the flow path opening / closing means after the scheduled time has elapsed and opens at the end of defrosting, and a defrost means that turns on immediately after the scheduled time elapses after the flow path opening / closing means closes and turns off at the end of defrosting. What is provided with the frost control means is disclosed.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention When a plurality of refrigerating units according to the conventional technique are simply mounted to form a large storage, defrosting operation in each refrigerating unit is only performed independently. , A refrigeration unit that performs a cooling operation and a refrigeration unit that performs a defrosting operation appear at the same time, and the cooling capacity of each refrigeration unit cannot be fully exerted, and each refrigeration unit independently Since the defrosting operation is started, the defrosting time in the refrigeration unit during the defrosting operation is extended due to the effect of cold air due to the cooling operation, or conversely, due to the effect of warm air in the refrigeration unit due to the defrosting operation, There are problems that the cooling efficiency of the refrigeration unit during the cooling operation decreases, or defrosting ends when frost remains on the cooler.

On the other hand, there is also a case where an after-mentioned time limiter for starting defrosting in a different cycle from the defrosting control means is provided to perform defrosting operation that cannot be compensated by each defrosting control means. Also in this case, the defrosting start of each refrigeration unit could not be synchronized.

In order to solve the problem caused by the defrosting operation being shifted for each refrigeration unit as described above, for example, JP-A-63-9646.
In the defrost control device for a connected refrigerated showcase disclosed in Japanese Patent Publication No. 8, when a plurality of showcases each having a defrosting unit are connected, an arbitrary one of the defrost control devices is wired at the time of wiring. The defrosting control device is used as a main control device, and the remaining defrosting control devices are used as slave control devices to synchronize the start of defrosting of the slave control device with the start of defrosting of the main control device.

However, when the main control device becomes inoperative due to a failure or the like, the sub control device starts defrosting individually at the defrost start time set for each, so that the main control device fails. When it becomes inoperative due to such reasons, it is necessary to inspect the main control unit and replace or repair the faulty part, or reconnect the wiring between each control unit and reset the main control unit, which makes maintenance management difficult. The problem of becoming complicated occurs. Also, when the main controller becomes inoperative, defrosting of each showcase is performed individually as before until the main controller is repaired or the main controller is reset as described above. The defrosting time of the showcase during the defrosting operation is extended, and conversely, the cooling efficiency of the showcase during the cooling operation is reduced due to the influence of warm air trapped in the showcase due to the defrosting operation. There is a problem that the defrosting operation ends when frost remains on the vessel.

Therefore, in the present invention, the defrosting control device for the cooling device is configured so that the start of the defrosting operation in the plurality of refrigerating units is performed in synchronization with each other, and which time period device is synchronized with each refrigerating unit can be selected. Is provided.

[Configuration of the Invention] Means for Solving the Problems The present invention provides a defrosting control circuit for a cooling device including a plurality of refrigerating units having a compressor, a condenser, an evaporator, a defrosting means, a controller, and the like. And a series circuit unit having a first timing device for controlling the start of defrosting of defrosting means provided for each controller and an opening / closing device for controlling energization of the first timing device; A time limiter capable of controlling the start of defrosting at a different cycle from the time limiter and setting a cycle, and a serial circuit unit and a synchronous circuit connected in parallel to the second time limiter, This synchronizing circuit synchronizes the defrosting start command in each controller based on the operation of the first timed device and the operation of the second timed device of the series circuit unit in which the switchgear is closed.

Action The second timing device is connected in parallel to each of the series circuit parts provided in each refrigeration unit by a synchronous circuit, so that the defrosting operation start time of each unit is the first or second. Of the refrigeration unit, and all the refrigeration units simultaneously start the defrosting operation.

Also, since the series circuit unit is provided with a switchgear,
When the first timed device that was operating becomes inoperative due to a failure or the like, it is possible to put another first timed device in the operating state by closing the opening / closing device of the other refrigeration unit. In addition, when a plurality of opening / closing devices are closed, when the first timed device provided in the controller of one refrigeration unit becomes inoperative, the controller of the other refrigeration unit can be operated. The provided first time device is brought into an operating state, the control of the defrosting operation is automatically switched, and the defrosting operation of each refrigeration unit can be started simultaneously at the same time. Further, depending on the combination of the open / closed state of the switchgear and the presence / absence of attachment of the second timing device, whether the defrosting operation is started by both the first and second timing devices or the defrosting operation is started only by the second timing device. A selection is made as to whether to start the defrosting operation only by the first time limiter, and the defrosting operation is started by the cycle setting according to the demand such as the season and the purpose of use.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

Reference numeral 1 is a prefabricated refrigerator / refrigerator, 2 is a cooling device, and each includes a compressor 3, a condenser 4, an evaporator 5, a condenser blower device 6, an evaporator blower device 7, a defrosting means 8 and a defrosting end detecting means ( A plurality of refrigerating units 10 including a cooling unit R (not shown) and a controller having a controller 9 and the like are prepared. In this example, 3 refrigeration units
Under the precondition that each has the same internal configuration, the explanation of one of them and the reference numeral will be attached to replace the whole explanation and to distinguish it from other refrigeration units. In the drawing, only the reference numeral 10 relating to the refrigerating unit is indicated in the drawing as 10A (representative), 10B,
Divided into 10C.

This cooling device 2 performs (I) cooling operation and (II) defrosting operation alternately, and performs temperature control so as to maintain the inside of the refrigerator-freezer 1 at a set temperature, which operation will be described later. It is controlled by the controller 9. The controller 9 is configured to alternately perform (I) cooling operation and (II) defrosting operation, but here, defrosting control for controlling the (II) defrosting operation of the cooling unit R is performed. Only the device S will be described.

FIG. 1 is a schematic circuit diagram of a defrosting control device S of a cooling device, in which each refrigeration unit 10 and a power supply (AC power supply here) 20
And a connection line 30 for connecting in parallel a second timing device 40 and each refrigeration unit R described later.

Each refrigeration unit 10 includes a cooling unit R and a controller 9
And a synchronization circuit 50.

The controller 9 is a central processing unit (illustrated by a CPU) 41
A RAM (random access memory) 42 and a ROM (read only memory) 43 that provide data to the central processing unit 41; and a first timed device (timer) for causing the cooling unit R to regularly perform defrosting. And 44). The controller 9 is connected with an opening / closing device 45 for switching the first time device 44 into a functional state (closed state) or a non-functional state (open state).

The first timing device 44 starts the timing operation from the end of the defrosting operation [after hot gas recovery operation after completion of defrosting when hot gas is used as defrosting means, and when power is turned on]. It starts to output a signal (for example, a count end signal) to the central processing unit 41 after a predetermined time has elapsed. The first time period device 44 can set the cycle in a predetermined range, for example, in a relatively short time range of about 1 hour to 15 hours.

The synchronization circuit 50 is connected to an AC power supply 20, and a transistor 51 whose base is connected to the output end of the controller 9, a relay coil 52 connected between the collector of the transistor 51 and a DC power supply (not shown). The relay contact 53 and the light emitting diode 54 are connected to each other, and the phototransistor 55 that conducts when the light emitting diode 54 emits light. The collector of the phototransistor 55 is connected to the DC power source through the resistor 56 and the controller 9 Is connected to the input end of. The light emitting diode 54 and the phototransistor 55 are so-called photocouplers P. Then, in each synchronization circuit 50, the relay contacts 53 are connected in parallel with each other via the connection line 30A, and the light emitting diodes 54 are connected with each other in parallel with each other via the connection line 30B.
The connection points of the light emitting diode 54 and the light emitting diode 54 are connected in parallel to each other by a connection line 30C. That is, connection line 30 (30A-30C)
Connects the synchronous circuits 50 to each other in parallel, and also connects the refrigeration units 10 to each other in parallel.

The second timing device 40 is connected to both ends of the relay contact 52, and causes the cooling unit R to periodically perform defrosting at a cycle different from that of the first timing device 44. The cycle can be set within a fixed range, for example, from one day to one week, which is a relatively long range as compared with the first time limiter 44. Moreover, unlike the first timing device 44, the timing operation is started from the time when the power is turned on, the contacts are closed after a certain period of time set as a cycle, and the contacts are opened after a predetermined period of time has elapsed. The opening / closing operation is continuously performed every set cycle. However, in the present embodiment, only one second time limit device 40 is connected, but this may be another plural number.

2 is a block-like circuit diagram of the defrosting control device S, in which the opening / closing device 45 and the first timing device 44 are connected in series for each refrigeration unit 10, and the series circuit part 47 is provided. The serial circuit section 47 and the second time limiter 40 are connected in parallel with each other.

The operation of the cooling device 2 will be described based on the above configuration. However, the refrigerator / refrigerator 1 appropriately stores stored items, and when defrost control is performed by both the first and second timing devices 44, 40, that is, at least one opening / closing device 45 is closed. When the time limit device 40 is connected [the setting period of the first time limit device 44 is, for example, 8 hours and the setting period of the second time limit device 40 is 2 days], the refrigeration unit 10A is used instead. explain.

(I) First, by turning on the operation start switch (not shown), a cooling command is output from the controller 9,
The cooling operation of the cooling unit R is started. By this cooling operation, the inside of the prefabricated refrigerator-freezer 1 is cooled to lower the temperature inside the refrigerator and maintain it at the set temperature.

(Ii) Then, after the cooling operation is started [when the power is turned on, from the time when the power is turned on], the first timing device 44 has started the time counting operation, and the set predetermined time (8 hours) has elapsed. Then, the timing device 44 outputs a count end signal to the central processing unit 41 (YES in step S2 of FIG. 3).
The central processing unit 41 outputs a defrosting synchronization command to the synchronization circuit 50 (see step S4 of FIG. 3), and
The count clear command of the time limiter 44 is output (see step S5 in FIG. 3). Then, after that, a defrosting start command is output to the cooling unit R (see step S6 in FIG. 3), and the cooling unit R stops the cooling operation (specifically, stops the compressor 3) based on this command, and The defrosting operation (specifically, the operation of the defrosting means 8) is started.

(Iii) On the other hand, in the synchronizing circuit 50, the transistor 51 becomes conductive and the relay coil 52 is energized by the synchronization command, the relay contact 53 closes, the light emitting diode 54 emits light, and the phototransistor 55 becomes conductive, and the input of the controller 9 is input. An L level signal (this is a so-called defrosting synchronization input) is input to the end. In addition, when the relay contact 53 is closed,
After passing through 30C, the photocoupler P of the synchronizing circuit in the other refrigerating units 10B and 10C is also energized, which means that the defrosting synchronizing input is inputted to the other controller.
The other cooling units R also stop the cooling operation and start the defrosting operation in synchronization with the previous cooling unit.

(Iv) Then, when the defrosting operation is continued and the defrosting is satisfactorily performed, and when the defrosting completion detecting means provided in each refrigeration unit 10 detects the defrosting completion, each cooling unit R independently defrosts. End the operation and return to the cooling operation independently. It should be noted that the first time limit device 44 provided in each refrigeration unit 10
Is to restart the time counting operation from the time when the defrosting ends, and if the defrosting ending time differs for each unit, the count end command of the time limit device of the refrigeration unit that finishes defrosting the earliest, The next defrosting start time will be determined.

(V) On the other hand, similarly to the first timing device 44, the second timing device 40 starts the time counting operation from the time when the power is turned on, and when a set fixed time [here, 2 days] has passed, its contact point Relay contacts 53 as previously closed for all sync circuits 50
When the photo coupler P receives an L level signal (this is the defrosting synchronization input, see step S3 in FIG. 3), the controller 9 operates in the same manner as when the controller 9 closes. Outputs a defrosting synchronization command to the cooling unit R (step S4), outputs a count clear command for the first timing device 44 (step S5), and then outputs a defrosting start command to the cooling unit R. (Step S6), based on this command, all the cooling units R simultaneously stop the cooling operation (specifically, the operation of the compressor 3) and simultaneously start the defrosting operation (specifically, the operation of the defrosting means 8). To do.

(Vi) Then, when the defrosting operation is continued and the defrosting is satisfactorily performed, and when the defrosting completion detecting means provided in each refrigeration unit 10 detects the defrosting completion, each cooling unit R independently defrosts. End the operation and return to the cooling operation independently. It should be noted that the first time limit device 44 provided in each refrigeration unit 10
Restarts the time counting operation from the time when the defrosting ends.

Hereinafter, the operations (i) to (vi) described above are repeated to maintain the internal temperature of the refrigerator-freezer 1 at the set temperature.

Next, when the defrosting control is performed only by the second time limiter 40, that is, when all the opening / closing devices 45 are opened and the second time limiter 40 is attached, (i) → (in the above description) The defrosting control is performed in the order of v) → (vi).

Further, when the defrosting control is performed only by the first timing device 44, that is, when the second timing device 40 is not attached and at least one of the opening / closing devices 45 is closed, (i) → (ii ) → (iii) → (iv) are defrosted in this order.

According to the above configuration, the second timing device 40 is connected in parallel by the synchronization circuit 50 to each of the series circuit parts 47 provided in each refrigeration unit 10,
The defrosting operation start time of each cooling unit R is determined by the first or second time limiter 44, 40. Further, since the series circuit unit 47 is provided with the switchgear 45, the open / closed states of the switchgear 45 and the second time limiter.
Depending on whether 40 is attached or not, the defrosting operation is started by both the first and second timing devices 44, 40, or the defrosting operation is started by the second timing device 40 only, or the first timing device 44 only. It is possible to start the defrosting operation by selecting the start time of the defrosting operation by setting the cycle according to the demand such as the season and the purpose of use.

Further, since the synchronization circuit 50 is provided, the defrosting synchronization input based on the end of counting of one timed device causes all the refrigeration units to start the defrosting operation at the same time. Due to this, the defrosting time in the refrigeration unit during the defrosting operation is extended, and conversely, the cooling efficiency of the refrigeration unit during the cooling operation is reduced due to the effect of warm air that is trapped in the refrigeration unit during the defrosting operation, It is possible to solve the problem that defrosting ends with frost remaining on the surface. In particular, the first time limit device 44 itself is pre-installed in each refrigeration unit 10, and the second time limit device 40 is connected to a commercially available timer.
Acts as an interface unit that connects both time limit devices 44, 40.

Further, when the first timing device 44 in the operating state fails, the opening / closing device 45 of the other refrigerating unit is closed, and the first timing device 44 and the synchronous circuit 50 are used in the same manner as before the occurrence of the failure. The defrosting operation of each refrigeration unit is synchronously performed based on the set cycle of the first time limiter 44, and it is possible to easily deal with the case where one of the first time limiters becomes inoperative due to a failure or the like. . Further, when the plurality of opening / closing devices 45 are closed in advance, when the first timed device 44 in the operating state becomes inoperative, the first timed device 44 provided in the controller 9 of another refrigeration unit is The operation state is entered, the control of the defrosting operation is automatically switched, and the defrosting operation of each refrigeration unit can be subsequently started simultaneously.

[Effects of the Invention] As described in detail above, according to the present invention, the second timing device is provided with respect to each of the series circuit units including the first timing device provided in each controller and the switchgear. Since the circuits are connected in parallel, the second timing device is the first
The time limiters are connected in parallel with each other, and as a result, the defrosting operation start of each cooling unit is determined by the first or second time limiter. Further, depending on the combination of the open / closed state of each opening / closing device and the presence / absence of attachment of the second time limit device, the defrost control device may start the defrost operation by both the first and second time limit devices, or the second time limit device. Whether to start the defrosting operation only by the device or the first timed device only will be selected, and the defrosting operation will be started at the cycle setting according to the demand such as the season and purpose of use. Is possible.

Further, since the synchronizing circuit is provided, all the refrigerating units start the defrosting operation at the same time by the defrosting synchronization input based on the end of counting of one timed device, and the cooling air generated by the cooling operation is reduced as in the conventional case. Due to this, the defrosting time in the refrigeration unit during the defrosting operation is extended, and conversely, the cooling efficiency of the refrigeration unit during the cooling operation is reduced due to the effect of warm air that is trapped in the refrigeration unit during the defrosting operation, It is possible to eliminate the inconvenience that the defrosting ends with the remaining frost.

Further, when the first timed device in the operating state fails, the first timed device is closed by closing the opening / closing device of the series circuit section provided in the controller of the other refrigeration unit as before the occurrence of the failure. , The second timing device and the synchronizing circuit can be operated, and the defrosting operation of each refrigeration unit is synchronously performed based on the set cycle of the first timing device and the second timing device, and the operation state of It is possible to easily deal with the case where the first time limiter changes to the inoperative state due to a failure or the like, and as a result, it is possible to simplify the maintenance management of the defrosting controller of the cooling device. Further, by closing the plurality of opening / closing devices in advance, even when the first timed device provided in the controller of one refrigeration unit becomes inoperable, the first device provided in the controller of the other refrigeration unit does not operate. When the defrosting operation of the refrigeration unit is automatically switched to the control of the defrosting operation of No. 1, the defrosting operation of each refrigeration unit can be simultaneously started, and as a result, when one failure occurs in the first timing apparatus. Even more easily, the maintenance of the defrost control device is further simplified, the defrost time that has been generated in the conventional cooling device is extended, and the cooling efficiency of the refrigeration unit during the cooling operation is improved. It is possible to surely solve the problem of deterioration.

[Brief description of drawings]

Each drawing shows an embodiment of the present invention, FIG. 1 and FIG. 2 are a schematic circuit diagram and a block circuit diagram of a defrosting control device of a cooling device, respectively, and FIG. 3 is a flow chart concerning defrosting of a controller, FIG. 4 is a sectional view showing a state in which a cooling device is installed in a refrigerator-freezer. DESCRIPTION OF SYMBOLS 1 ... Prefabricated refrigerator / freezer, 2 ... Cooling device, S ... Defrosting control device, R ... Cooling unit, 8 ... Defrosting device, 9 ... Controller, 10, 10A-10C ... Refrigeration unit, 40 ... Second time device, 44 ... 1st timing device, 45 ... Switchgear, 47 ... Series circuit part, 50 ... Synchronous circuit.

Claims (1)

[Claims] 1. A cooling device comprising a plurality of refrigerating units having a compressor, a condenser, an evaporator, a defrosting means, a controller, etc., which is provided for each controller and controls defrosting start of the defrosting means. A first circuit and a series circuit unit having a switchgear for controlling energization to the first timer; and a second circuit capable of controlling the defrosting start at a cycle different from that of the first timer and setting the cycle. And a synchronizing circuit connected in parallel to each of the series circuit units and the second timing unit, the synchronizing circuit of the first timing unit of the series circuit unit in which the switchgear is closed. A defrosting control device for a cooling device, which synchronizes a defrosting start command in each controller based on the operation and the operation of the second timing device.