JPH0253706B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refrigeration system that performs cycle control of intermittent cooling operation, defrosting operation, and draining process.

Various methods of cycle control in this type of refrigeration apparatus have been proposed in the past.

That is, a first timer that integrates the intermittent cooling operation time and, when the integrated value reaches a predetermined value, instructs the start of the defrosting operation;
When this value reaches a predetermined value, a second timer causes the process to proceed to the next draining process; a third timer integrates the draining time; and when the predetermined value is reached, the defrosting operation is terminated and the transition is made to the cooling operation; Generally, a temperature switch is used that detects the temperature of the cooler and, when the detected temperature rises to a predetermined temperature, shifts to the draining process.

In this case, the temperature switch is normally adjusted to issue a command before the second timer commands the transition to draining, and the second timer is adjusted so that the temperature switch issues a command in the unlikely event that the temperature switch malfunctions. This is used to prevent the heating operation from continuing if it becomes activated.

As mentioned above, conventional methods use a large number of timers, resulting in high costs and
There was a problem that reliability decreased depending on the accuracy of each individual timer.

This invention was developed in consideration of the above-mentioned circumstances, and the cycle control of cooling operation, defrosting operation, and water draining process was conventionally achieved using at least three timers, but even if the power supply is interrupted, After re-energizing, when the energizing time is accumulated and the total energizing time of the predetermined cooling operation time is reached, the time-limited contact is closed, and after the above-mentioned total energizing time has elapsed, the defrosting operation time and draining process time shorter than the above-mentioned total energizing time are added. It is an object of the present invention to provide an inexpensive and highly reliable refrigeration system that can be used with only one timer to open the time-limited contact when a set time, which is the sum of , has elapsed.

Hereinafter, embodiments of the refrigeration system of the present invention will be described based on the drawings.

The figure is a circuit diagram showing the configuration of one embodiment.
1 in the figure is an AC power supply, one electrode of which is connected to the line _L1 via the operation switch 2, and this line _L1 is connected to the contact 5- of the first relay 5.
3 (normally closed) to line L ₂ .
The other electrode of the AC power source 1 is connected to line _L3 .

Between lines L ₁ and L ₃ , motor 3 of timer 3 is connected.
1 and the contact 10-2 (normally open) of the electromagnetic switch 10 are connected in series.

The timer 3 has a motor 3-1 and a time-limiting contact 3-2, which is connected between the line _L1 and the movable contact c of the temperature switch 4. When the energization time of the motor 3-1 reaches a predetermined cooling operation time, specifically 4 hours in total, the time limit contact 3-2 closes, and the motor 3-1 further closes the circuit for a set time which is the sum of the defrosting operation time and the draining process time. Specifically, after 15 minutes, the circuit opens again and returns to its original state. This has been repeated ever since. Then, even if the power supply to the motor 3-1 is interrupted, this timer 3
The integration is not canceled, and when energization is resumed, the integration value from then on is added to the previous integration value.

The temperature switching circuit 4 has a movable contact c and two fixed contacts a and b, and is activated by detecting the temperature of a cooler (not shown), when the detected temperature reaches a predetermined high temperature value of 10°C. When this is the case, the movable contact c connects with the fixed contact b, and when the temperature falls below a predetermined low temperature value of 0° C., the movable contact c connects with the fixed contact a.

The fixed contact a of the temperature switch 4 is connected in series to the contact 5-4 (normally closed) of the first relay 5 and the coil 6-1 of the second relay 6, and is connected to the line _L3 . This first relay 5 has a coil 5-
1. It has contacts 5-2 to 5-5, and the coil 5
When -1 is energized, contacts 5-2 and 5-5 are closed, and contacts 5-3 and 5-4 are opened. Contact 5-2 is connected between movable contact c and fixed contact b of temperature switch 4, and this fixed contact b
The coil 5-1 is connected to the line _L3 via the coil 5-1. In addition, the contact 5-5 is connected to the connection line between the motor 3-1 and the contact 10-2 of the electromagnetic switch 10.
It is connected in parallel with contact 10-2 between _L3 .

The second relay 6 has a coil 6-1 and a contact 6.
-2 to 6-4, and when the coil 6-1 is energized, the contact 6-2 closes, and the contacts 6-3,
6-4 is designed to open. Contact 6-2
A series circuit of the hot gas solenoid valve 7, which is a heating means of the cooler, is connected between the lines _L2 and _L3 .
Similarly, a series circuit between the contact point 6-3 and the cooler blower 8 is connected. In addition, the series circuit between the contact 6-4 and the condenser blower 9 is connected to lines _L2 and _L4.
connected between. Line L ₄ is temperature controller 1
1 to line L ₃ .

Further, the electromagnetic switch 10 is for opening and closing an electric circuit of a compressor motor (not shown),
It has a coil 10-1 and a contact 12-2.
When the coil 10-1 is energized, the contact 10-2 closes, and the compressor motor is driven through the electric circuit to operate the compressor. Coil 10-1 is connected between lines _L2 and _L4 .

The temperature regulator 11 is activated by detecting the temperature inside the refrigerator, and when the detected temperature drops to -22°C, the contact 11-1 opens, and when it rises to -18°C, it closes. .

Next, the operation of the refrigeration system of this embodiment configured as above will be explained. Before the start of operation, both the temperature of the air inside the refrigerator and the cooler (not shown) are high, so the contact 11-1 is closed, and the movable contact c of the temperature switch 4 is closed to the fixed contact b side (state shown). ing. Further, the time limit contact 3-2 of the timer 3 is also open since the motor 3-1 is not energized.

When the operation switch 2 is turned on in this state, since the contact 3-2 of the timer 3 is open, both the coil 5-1 of the first relay 5 and the coil 6-1 of the second relay 6 are not energized. Therefore, the cooler blower 8 and the condenser blower 9 are started. The coil 10-1 of the electromagnetic switch 10 is also energized. By energizing the coil 10-1, the compressor (not shown) is also started, and cooling operation is started.
At the same time, the coil 10-1 is energized to close the contact 10-2. By closing this contact 10-2, the motor 3-1 of the timer 3 is energized, and the integration of the energization time is also started.

In this way, when the cooling operation is performed, the temperature of the cooler decreases. When the temperature of the cooler falls below a predetermined low temperature value of 0° C., this is detected and the movable contact c of the temperature switch 4 is switched from the fixed contact b to the a side. In addition, the temperature inside the refrigerator gradually decreases,
When the temperature reaches -22℃, contact 11-1 of temperature controller 11
is opened and the condenser blower 9 is stopped.

At the same time, the coil 10-1 of the electromagnetic switch 10 is deenergized to open the electric circuit, the compressor stops, and at the same time, the contact 10-2 opens and the motor 3- of the timer 3
1 is deenergized and the integration of cooling operation time is interrupted.

Due to this interruption of the cooling operation, the temperature inside the refrigerator rises and reaches -18°C, when the contact point of the temperature controller 11
-1 is closed. As a result, the compressor and the condenser blower 9 are started, and the cooling operation is restarted, and the motor 3-1 of the timer 3 is energized and the integration of the cooling operation time is restarted. Repeat this thereafter.

During this time, frost builds up on the cooler, and the amount increases as the total cooling operation time increases. When the total cooling operation time reaches 4 hours, which is the predetermined cooling operation time of the timer 3, the time limit contact 3-2 of the timer 3 closes. At this time, as described above, the movable contact c of the temperature switch 4 is closed to the fixed contact a side, so the coil 5-1 of the first relay 5 is not energized, and the coil of the second relay 6 is closed. 6-1 is energized. Therefore, contact 6-2 is closed, and contact 6-2 is closed.
-3 and 6-4 are opened.

As a result, while the cooler blower 8 and the condenser blower 9 are stopped and the compressor is operated,
The hot gas electromagnetic valve 7, which is the heating means of the cooler, is energized and opened, hot gas is supplied to the cooler, and defrosting operation is started. This defrosting operation melts the frost and increases the temperature of the cooler.
When the temperature reaches a predetermined high temperature value of 10° C. or higher, this is detected and the movable contact c of the temperature switch 4 is switched to the fixed contact b side to close the circuit. Along with this, the coil 5-1 of the first relay 5 is energized, and the second relay 6 is energized.
coil 6-1 is deenergized.

When the coil 5-1 of the first relay 5 is energized, its contact 5-3 is opened, the energization to the electromagnetic switch 10 is cut off, the electrical circuit of the compressor is also cut off, and the compressor is stopped. . The hot gas solenoid valve 7 is also deenergized, closing the valve and preventing hot gas from being supplied to the cooler. Furthermore, the cooler blower 8
and the condenser blower 9 are connected as they are in the stopped state. That is, a draining process is performed.

In this draining process, contact 1 of the electromagnetic switch 10
0-1 is opened, but instead, the contact 5-5 of the first relay 5 is closed, so the timer 3 continues to be energized to the motor 3-1, and the integration of the set time is continued. . Then, when the time since the transition to the above-mentioned defrosting operation reaches 15 minutes,
The time limit contact 3-2 of the timer 3 is opened, and the coil 5-1 of the first relay 5 is no longer energized.
Contacts 5-2, 5-5 open, contacts 5-3, 5-
4 is closed, a transition to cooling operation is performed.

In the case of this device, the switching of the movable contact c of the temperature switch 4 from the fixed contact a to b starts from the start of defrosting.
It takes about 10 minutes. Therefore, draining is 5
It takes about a minute or so.

In the case of a refrigeration system in which the heating and melting time of the frost formed on the cooler, that is, the defrosting operation time becomes longer, the closing time of the time limit contact 3-2 of the timer 3 may be set to be correspondingly longer.

During the above draining process, the cooler is cooled by the air inside the refrigerator, and even if the temperature drops to the predetermined low temperature value of 0°C, and the movable contact c of the temperature switch 4 is reversed from the fixed contact b to the a side, Since the contact 5-2 is closed, the coil 5-1 is energized as it is, and since the contact 5-4 is open, the coil 6-1 of the second relay 6 is energized.
is not energized. That is, the draining process continues as is.

During the above defrosting operation and draining process, the temperature switch 4 is malfunctioning and the detected temperature is 10℃, which is the predetermined high temperature value.
Even if the movable contact c of the temperature switch 4 does not switch from the fixed contact a to the fixed contact b, even if the temperature switch 4 reaches
The time limit contact 3-2 is opened and the cooling operation begins. That is, even if the temperature switch 4 becomes inoperative, the defrosting or heating operation will not continue, and melting of the storage container will be prevented.

As explained above, according to the present invention, cycle control of intermittent cooling operation, defrosting operation, and water draining process is performed, and the compressor is operated during the cooling operation and the defrosting operation, and the compressor is operated during the water draining process. In a refrigeration system for stopping a machine, a temperature switch detects the temperature of the cooler and switches when the detected temperature reaches a predetermined low temperature value and a predetermined high temperature value, an electromagnetic switch that controls the operation of the compressor, and a predetermined temperature switch. It has a time-limited contact that closes after the cooling operation time has elapsed and opens when a set time that is the sum of the defrosting operation time and the draining process time has elapsed, and is energized when the electromagnetic switch is energized. a timer that integrates the time and closes the time limit contact when the predetermined cooling operation time is reached; and a temperature switch that closes the time limit contact when the time limit contact of the timer is closed and the detected temperature of the cooler is below a predetermined low temperature value. When the detected temperature of the cooler reaches a predetermined high temperature value or higher due to the defrosting operation, the heating means of the cooler is energized and the heating means is energized to perform a defrosting operation. a second relay that de-energizes the means to end the defrosting operation, and a detected temperature of the cooler due to the defrosting operation while the time limit contact of the timer is closed;
When the temperature reaches a predetermined high temperature value or higher, the temperature switch is energized, the electromagnetic switch is deenergized, the compressor is stopped, and the timer is continuously energized to carry out the draining process, and the timer is activated. By providing the first relay that switches to cooling operation when the time-limited contact opens after the set time has elapsed, only one timer is required compared to three in the past, so the number of individual timers can be reduced. It is possible to provide a refrigeration system whose reliability does not deteriorate due to accuracy.

[Brief explanation of drawings]

The figure is a circuit diagram of an embodiment of the refrigeration system of the present invention. 1...AC power supply, 2...operation switch, 3...
Timer, 4... Temperature switch, 5... First relay, 6... Second relay, 7... Hot gas solenoid valve, 8... Cooler blower, 9... Condenser blower, 10... Solenoid Switch, 11...Temperature controller.

Claims (1)

[Claims] 1 In a refrigeration system that performs cycle control of intermittent cooling operation, defrosting operation, and draining process, operating the compressor in the cooling operation and defrosting operation, and stopping the compressor in the draining process, the cooler a temperature switch that detects the temperature of the compressor and switches when the detected temperature reaches a predetermined low temperature value and a predetermined high temperature value, and an electromagnetic switch that controls the operation of the compressor;
It has a time-limited contact that closes after a predetermined cooling operation time has elapsed and opens when a set time that is the sum of the defrosting operation time and the draining process time has elapsed, and is energized when the electromagnetic switch is energized. A timer that integrates the energization time and closes the time-limited contact when the predetermined cooling operation time is reached, and when the time-limited contact of this timer is closed and the detected temperature of the cooler is below the predetermined low temperature value, the temperature is increased. The heating means of the cooler is energized by the switch to perform defrosting operation, and when the detected temperature of the cooler becomes equal to or higher than the predetermined high temperature value due to the defrosting operation, the temperature switch deenergizes the heating means of the cooler. a second relay that deenergizes the heating means to terminate the defrosting operation;
When the detected temperature of the cooler exceeds the predetermined high temperature value due to defrosting operation while the time limit contact of the timer is closed, the temperature switch is energized, the electromagnetic switch is deenergized, and the compressor is compressed. and a first relay that stops the operation of the machine and continuously energizes the timer to perform a water draining process, and when the set time of the timer elapses and the time limit contact opens, the system shifts to cooling operation. A refrigeration device characterized by: