JP2005134091A - Cooling storage device and operation control method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid the overload operation of a compressor in a cooling storage device of a type for cooling a plurality of storages by one freezer and an operation control method therefor. <P>SOLUTION: When it is detected that the inside temperature is higher than a pull-down temperature by a temperature sensor 20, a large cooling load is determined, and a program for pull-down is executed. A first solenoid valve 18A is opened, and a compressor 11 is started, and a refrigerant is carried only to a first cooler 14A to cool only a first cooling chamber 10A. When 10 minutes passes, or when the inside temperature of the first cooling chamber 10A is lowered to an upper limit temperature, a second solenoid valve 18B is opened, and the first solenoid valve 18A is successively closed. Thereafter, the refrigerant is carried only to a second cooler 14B to cool only a second cooling chamber 10B. When the same condition is established, the first solenoid valve 18A is opened again. In the pull-down control, the refrigerant is alternately carried to the first cooler 14A and the second cooler 14B within 10 minutes at a maximum, and the overload operation of the compressor 11 can be thus avoided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a cooling storage device of a type that cools a plurality of storages with a single refrigeration device, and an operation control method thereof.

The following are known as one type of cooling storage device. This can be equipped with one refrigeration unit having a compressor, a condenser, etc., while two refrigeration units are connected to the refrigeration unit via electromagnetic valves, and each chiller is an independent storage. It is the structure arranged in. In each storage, the corresponding electromagnetic valve is opened and closed depending on whether the internal temperature detected by the temperature sensor is higher or lower than a preset temperature, and the flow and stop of the refrigerant to the cooler are controlled. As a result, the inside of the cabinet is maintained at a substantially set temperature.
In addition, this kind of cooling storage apparatus is described in patent document 1 grade | etc.,.
JP 2002-295941 A

By the way, in this kind of cooling storage device, depending on the cooling conditions of both storages, both solenoid valves may be opened and the refrigerant will flow through the coolers of both storages, in other words, both coolers may be working together. . However, this is because the so-called control operation in which the interior of each storage is maintained near the set temperature is still high, for example, when the cooling storage device is installed for the first time in summer, the internal temperatures of both storages are considerably high. When trying to cool from the state to the set temperature (pull-down operation), the compressor is overloaded, and the protection device may be activated and stopped.
The present invention has been completed based on the above circumstances, and its object is to avoid overload operation of the compressor.

  As a means for achieving the above object, an operation control method for a cooling storage device according to the invention of claim 1 is an independent storage in which a plurality of coolers are connected to a common refrigeration device having a compressor or the like. In the cooling storage device, each of the corresponding storages is cooled to a set temperature by controlling the circulation and stoppage of the refrigerant to each cooler, the cooling load related to the storage is If the number is greater than or equal to a predetermined value, the number of coolers through which the refrigerant is circulated is limited, and the coolers through which the refrigerant can be circulated are controlled to be sequentially replaced.

  In the invention of claim 2, a plurality of coolers are connected to a common refrigeration apparatus having a compressor or the like via respective electromagnetic valves, and each cooler is arranged in an independent storage, Based on the output of the temperature sensor that detects the internal temperature, the corresponding solenoid valve is opened and closed to control the flow and stop of the refrigerant to the cooler, so that the internal temperature is maintained at the set temperature. In the cooling storage device, if the detection value of the load detection means for detecting the cooling load related to the storage and the detection value of the load detection means is greater than or equal to a predetermined value, the number of solenoid valves opened simultaneously can be limited and opened. And a valve drive control means for sequentially replacing the solenoid valves.

  According to a third aspect of the present invention, in the second aspect, the valve drive control means outputs a control signal for restricting the opening of the other solenoid valve while the one solenoid valve is open. In addition, when the opening time of the one electromagnetic valve elapses for a predetermined time or when the internal temperature of the storage provided with the one electromagnetic valve decreases below a predetermined value, the control signal is stopped and another electromagnetic valve is stopped. It is characterized in that it has a function of allowing the opening of the first solenoid valve and then closing the one solenoid valve.

The invention of claim 4 is characterized in that, in the invention of claim 3, a communication unit is provided in each storage, and the control signal and the like are communicable between the communication units.
The invention of claim 5 is characterized in that, in any of claims 2 to 4, the cooling load is determined based on an output of the temperature sensor.

<Invention of Claim 1>
When the cooling load becomes equal to or greater than a predetermined value, the number of coolers through which the refrigerant is circulated is limited, and the refrigerant is circulated alternately to each chiller, and each storage is replaced and cooled. For example, when a pull-down operation for cooling from a state where the inside temperature is considerably high to a set temperature is necessary, it is possible to sequentially circulate some of the coolers sequentially instead of circulating the refrigerant to all the coolers at the same time. Therefore, it is avoided that the compressor is overloaded. Therefore, the operation of the compressor is ensured without being stopped by the protection device, and pull-down cooling can be performed reliably.

<Invention of Claim 2>
When it is detected by the load detection means that the cooling load is greater than or equal to the predetermined value, the valve drive control means allows the solenoid valves to be opened alternately while limiting the number of solenoid valves to be opened simultaneously, and the corresponding cooler As the refrigerant is circulated, each storage is replaced and cooled.
When pull-down operation is required to cool the chamber temperature from a considerably high state to the set temperature, not all solenoid valves are opened at the same time, but some solenoid valves can be opened sequentially. Since the refrigerant can be circulated sequentially for each cooler, the compressor can be prevented from being overloaded. Therefore, the operation of the compressor is ensured without being stopped by the protection device, and pull-down cooling can be performed reliably.

<Invention of Claim 3>
When it is detected that the cooling load is greater than or equal to a predetermined value and one of the solenoid valves is first opened, a control signal is issued while the solenoid valve is open, thereby restricting the opening of the other solenoid valves. When the opening time of one solenoid valve elapses for a predetermined time or the internal temperature of the storage provided with this one solenoid valve drops below a predetermined value, the control signal is stopped to allow other solenoid valves to be opened. Therefore, if a condition such as a high temperature inside the storage provided with another electromagnetic valve is satisfied, the other electromagnetic valve is opened, and then one electromagnetic valve is closed. By repeating this, each solenoid valve is alternately opened.

<Invention of Claim 4>
Each solenoid valve is controlled to open and close while exchanging control signals and the like between the communication units.
<Invention of Claim 5>
The magnitude of the cooling load is determined based on the output of the temperature sensor provided in the storage.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 3.
In this embodiment, as shown in FIG. 1, two units of a first refrigerator 10A and a second refrigerator 10B are provided. On the other hand, the refrigeration circuit for cooling the refrigerators 10A and 10B has a structure in which the compressor 11, the condenser 12, the expansion mechanism 13 (capillary tube), and the cooler 14 (evaporator) are circulated and connected by refrigerant piping. However, among these, the compressor 11 and the condenser 12 are one each, and the common refrigeration apparatus 15 said to this invention is comprised by both. On the other hand, two expansion mechanisms 13 and two coolers 14 are provided, and two sets in which the expansion mechanism 13 and the cooler 14 are connected in series are formed. The outlet and the inlet of the compressor 11 are connected in parallel.

In the refrigeration circuit described above, one cooler 14A (hereinafter referred to as the first cooler 14A) is provided in the first refrigerator 10A, and the other cooler 14B (hereinafter referred to as the second cooler 14B) is provided in the second refrigerator 10B. is set up. Further, the first electromagnetic valve 18A is provided on the pipe 17A on the first cooler 14A side, and the second electromagnetic valve 18B is provided on the upstream side of the expansion mechanism 13 on the pipe 17B on the second cooler 14B side. .
The refrigerators 10A and 10B are provided with first and second temperature sensors 20A and 20B that detect the internal temperature of the refrigerator.

Each refrigerator 10A, 10B is equipped with signal input / output units 22A, 22B, respectively. The signal input / output units 22A and 22B include input lines 23A and 23B from the corresponding internal temperature sensors 20A and 20B, output lines 24A and 24B to the electromagnetic valves 18A and 18B, and output lines to the compressor 11, respectively. 25A and 25B are connected. The signal input / output units 22A and 22B are connected by a communication line 27 so as to be capable of bidirectional communication. Therefore, the signal input / output units 22A and 22B also serve as the communication unit of the present application.
On the other hand, a control unit 30 storing a program for performing control as described later is provided and connected to both the signal input / output units 22A and 22B.

First, the operation at the time of the control operation for maintaining the inside temperatures of the refrigerators 10A and 10B at substantially the set temperature will be described with reference to the timing chart of FIG.
As a basic operation, in both the first refrigerator 10A and the second refrigerator 10B, if the internal temperature detected by the temperature sensors 20A and 20B rises to an upper limit temperature higher than the set temperature by a predetermined value, the corresponding electromagnetic When the valves 18A and 18B are turned on (opened) and conversely fall to a lower limit temperature lower than the set temperature by a predetermined value, the electromagnetic valves 18A and 18B are turned off (closed). When either one of the solenoid valves 18A and 18B is turned on, the compressor 11 is turned on (started), and when both the solenoid valves 18A and 18B are turned off, the compressor 11 is turned off (stopped). .

  Here, the compressor 11 is continuously operated for 20 seconds or more for protection. Conversely, once it is stopped, it takes 120 seconds to stop. Therefore, when the solenoid valves 18A and 18B are turned off in the refrigerators 10A and 10B, the corresponding signal input / output units 22A and 22B output “H” signals as control signals for 120 seconds, and the opposite signal input / outputs. The parts 22A and 22B are input as “L” signals. On the side where the “L” signal is input, the solenoid valves 18A and 18B are not turned on for 120 seconds, and therefore the compressor 11 is not turned on (activated).

  In addition, there is a time lag from when one of the two solenoid valves 18A, 18B is turned off until the control signal “H” is output, and when the other solenoid valve 18A, 18B is turned on by striking the gap, the compressor In order to avoid this phenomenon, the control signal “H” is output for 1 second before the solenoid valves 18A and 18B are turned off. Is output. In other words, when the internal temperature falls to the lower limit temperature, the control signal “H” is output, and the solenoid valves 18A and 18B are turned off with a delay of 1 second.

According to the timing chart of FIG. 2, when the internal temperature of the first refrigerator 10A rises to the upper limit temperature (timing t1), the first electromagnetic valve 18A is turned on, the compressor 11 is turned on, and the first cooler 14A is turned on. The refrigerant is supplied to cool the inside of the first refrigerator 10A. Subsequently, similarly, when the internal temperature of the second refrigerator 10B rises to the upper limit temperature (timing t2), the second electromagnetic valve 18B is turned on, and the refrigerant is also supplied to the second cooler 14B, so that the inside of the second refrigerator 10B. Is cooled.
After that, when the internal temperature of the first refrigerator 10A falls to the lower limit temperature (timing t3), a control signal “H” is issued from the first refrigerator 10A side, and the first electromagnetic valve 18A is turned off after 1 second. (Timing t4). Furthermore, an “H” signal is output for 120 seconds. Similarly, when the internal temperature of the second refrigerator 10B falls to the lower limit temperature, the control signal “H” is issued from the second refrigerator 10B side, and the second electromagnetic valve 18B is turned off 1 second later (timing t5). . Along with this, the compressor 11 is turned off and stopped. Furthermore, an “H” signal is output for 120 seconds.

Thereafter, the same operation as described above is repeated. However, after both the solenoid valves 18A and 18B are closed and the compressor 11 is stopped (timing t6), before the elapse of 120 seconds, for example, the internal temperature of the first refrigerator 10A in which the first solenoid valve 18A is closed first is Even if the temperature reaches the upper limit temperature (timing t7), the first electromagnetic valve 18A is not turned on, and therefore the compressor 11 is not turned on. The first solenoid valve 18A is turned on only after 120 seconds elapses, and the compressor 11 is also turned on (timing t8).
During the control operation, the above-described operation is repeated, and the internal temperatures of the first refrigerator 10A and the second refrigerator 10B are maintained substantially at the set temperatures.

Now, in this embodiment, when cooling from the state where both the refrigerators 10A and 10B have a high internal temperature to the vicinity of the set temperature, that is, when performing pull-down operation, measures are taken to prevent the compressor 11 from being overloaded. ing.
Therefore, the pull-down operation is controlled by a program different from the control operation described above.

Hereinafter, the operation in the pull-down operation will be described with reference to the timing chart of FIG.
If the internal temperature of either one of the first refrigerator 10A and the second refrigerator 10B exceeds a pull-down temperature that is higher than the upper limit temperature by a predetermined value, a program for pull-down operation is executed. 10A and the first solenoid valve 18A and the second solenoid valve 18B equipped in the second refrigerator 10B are alternately turned on (opened) alternately for 10 minutes at the longest (more precisely, 10 minutes and 2 seconds as will be described later). The

  In this program, as in the control operation described above, the compressor 11 takes a continuous operation of 20 seconds or more and a stop time of 120 seconds or more for protection. Therefore, as described above, when the solenoid valves 18A and 18B are turned off, the control signal “H” is output from the corresponding signal input / output units 22A and 22B for 120 seconds, and accordingly, the opposite signal input / output unit 22A. , 22B is input as an “L” signal, and the corresponding solenoid valves 18A, 18B are restricted from being turned on during that time. In addition, in order to prevent the instantaneous stop of the compressor 11, the control signal “H” is output for 1 second before the solenoid valves 18A and 18B are turned off (hereinafter, referred to as the subsequent 1 second). is there.

  In addition, in the program for pull-down operation, while each solenoid valve 18A, 18B is on, the control signal “H” is output from the corresponding signal input / output unit 22A, 22B. The parts 22A and 22B are input as “L” signals, and the corresponding solenoid valves 18A and 18B are restricted from being turned on during that time. However, the control signal “L” is output for 1 second (hereinafter referred to as the previous 1 second) from 2 seconds before the electromagnetic valves 18A and 18B are turned off. Accordingly, “H” signals are input to the signal input / output units 22A and 22B on the opposite side, and during that time, the corresponding solenoid valves 18A and 18B can be turned on. At this time, the condition that the electromagnetic valves 18A and 18B are turned on is that the internal temperature of the corresponding refrigerators 10A and 10B is equal to or higher than the upper limit temperature.

  In addition, in the previous 1 second before one solenoid valve 18A, 18B is turned off, if the inside temperature of the refrigerators 10A, 10B on the opposite side is lower than the upper limit temperature or the defrosting operation is in progress Since the solenoid valves 18A and 18B are not turned on, the compressor 11 is turned off when one of the solenoid valves 18A and 18B is turned off. In this case as well, the control signal “H” for 120 seconds is output. If the other solenoid valve 18A, 18B is turned on until the time until it is output, the compressor 11 will also exhibit an instantaneous stop phenomenon, and in order to avoid it, the subsequent control signal “H” for 1 second is output. Becomes effective.

Control during pull-down operation will be described with reference to the timing chart of FIG. During the pull-down operation, for example, it is determined that the first electromagnetic valve 18A of the first refrigerator 10A is turned on first, and the second electromagnetic valve 18B of the second refrigerator 10B is turned on later.
When the program for pull-down operation is executed from the internal temperature condition, first, when the power is turned on (timing T1), the control signal “H” is output from the signal input / output unit 22A on the first refrigerator 10A side, When 120 seconds elapse (timing T2), the first electromagnetic valve 18A is turned on, the compressor 11 is turned on, the refrigerant is supplied to the first cooler 14A, and the inside of the first refrigerator 10A is cooled. The control signal “H” is continuously output.

  Even if the internal temperature of the first refrigerator 10A is still higher than the upper limit temperature, when 10 minutes have passed since the first electromagnetic valve 18A was turned on (timing T3), the control signal “L” is 1 from the first refrigerator 10A side. Is output for one second (the previous one second), and accordingly, the control signal “H” is input to the second refrigerator 10B side. At this time, if the internal temperature of the second refrigerator 10B is equal to or higher than the upper limit temperature, the second electromagnetic valve 18B is turned on, and the control signal “H” is continuously output from the second refrigerator 10B side. After that, the first electromagnetic valve 18A is turned off after the next one second (timing T4), and then the refrigerant is supplied only to the second cooler 14B and only the inside of the second refrigerator 10B is cooled.

  When 10 minutes have elapsed after the second electromagnetic valve 18B is turned on, or when the internal temperature of the second refrigerator 10B falls below the upper limit temperature (timing T5), the control signal “L” is sent from the second refrigerator 10B side. The signal is output for one second (the previous one second), and accordingly, the control signal “H” is input to the first refrigerator 10A side. At this time, if the internal temperature of the first refrigerator 10A is equal to or higher than the upper limit temperature, the first electromagnetic valve 18A is turned on, and the control signal “H” is continuously output from the first refrigerator 10A side. After that, the second electromagnetic valve 18B is turned off after the next one second (timing T6), and then the refrigerant is supplied only to the first cooler 14A and only the first refrigerator 10A is cooled.

After that, when the internal temperature of the first refrigerator 10A falls to the upper limit temperature (timing T7), the control signal “L” is output from the first refrigerator 10A side for 1 second (previous 1 second), and accordingly the second refrigerator The control signal “H” is input to the 10B side. At this time, if the internal temperature of the second refrigerator 10B is lower than the upper limit temperature, the second electromagnetic valve 18B remains off. After that, the first electromagnetic valve 18A is also turned off after the subsequent one second, and the compressor 11 is also stopped. The pull-down operation ends when both the solenoid valves 18A and 18B are turned off together.
Thereafter, after the compressor 11 has been stopped for 120 seconds, the control operation described above is performed.

  As described above, according to the present embodiment, when it is necessary to perform a pull-down operation, the first electromagnetic valve 18A and the second electromagnetic valve 18B can be opened alternately, that is, the first cooler 14A and the first cooler 14A. Since the refrigerant is circulated alternately to the two coolers 14B, the compressor 11 is prevented from being overloaded. Therefore, the operation of the compressor 11 is ensured without being stopped by the protective device, and as a result, pull-down cooling can be reliably performed in the refrigerators 10A and 10B.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
(1) In the above embodiment, the cooling load serving as a trigger for entering the pull-down cooling control is equal to or higher than a predetermined value, and the internal temperature of at least one refrigerator is equal to or higher than the pull-down temperature higher than the upper limit temperature by a predetermined value. In addition to this, it is possible to set an appropriate one according to the conditions such as the inside temperature of both refrigerators being equal to or higher than the pull-down temperature or using the upper limit temperature instead of the pull-down temperature. .

(2) In the pull-down operation, the time for which the solenoid valve is continuously opened is set to 10 minutes at a maximum, and other appropriate time may be set.
(3) Both signal input / output sections may be shared so that no communication function is provided, and such a structure is also included in the technical scope of the present invention.
(4) The present invention can be similarly applied to a cooling storage device in which three or more storages are cooled by one refrigeration device.

System block diagram of one embodiment of the present invention Timing chart during control operation Timing chart for pull-down operation and transition to control operation

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10A, 10B ... Refrigerator (storage) 11 ... Compressor 14A, 14B ... Cooler 15 ... Refrigeration apparatus 18A, 18B ... Solenoid valve 20A, 20B ... Temperature sensor (load detection means) 22A, 22B ... Signal input / output part (communication part) 30 ... Control unit (valve drive control means)

Claims (5)

A plurality of coolers are connected to a common refrigeration apparatus having a compressor or the like and are arranged in independent storages, and each corresponding storage is controlled by controlling the circulation and stoppage of the refrigerant to each cooler. In a cooling storage device that is cooled to a set temperature,
When the cooling load related to the storage is greater than or equal to a predetermined value, the number of coolers through which the refrigerant is circulated is restricted at the same time, and the coolers in which the refrigerant can be circulated are sequentially controlled. An operation control method for a cooling storage device. A plurality of coolers are connected to a common refrigeration apparatus having a compressor or the like via respective solenoid valves, and each cooler is disposed in an independent storage. In each storage, the temperature at which the internal temperature is detected. In the cooling storage device in which the corresponding solenoid valve is opened and closed based on the output of the sensor and the flow and stop of the refrigerant to the cooler are controlled, so that the interior is maintained at the set temperature.
Load detecting means for detecting a cooling load related to the storage; and
When the detection value of the load detection means is equal to or greater than a predetermined value, there is provided a valve drive control means for limiting the number of solenoid valves that are simultaneously opened and sequentially changing the solenoid valves that can be opened. A cooling storage device. While the one solenoid valve is open, the valve drive control means outputs a control signal for restricting the opening of the other solenoid valve, and whether the opening time of the one solenoid valve elapses for a predetermined time. Alternatively, when the internal temperature of the storage provided with the one solenoid valve is lowered below a predetermined value, the control signal is stopped, the other solenoid valve is allowed to open, and then the one solenoid valve is closed. The cooling storage device according to claim 2, further comprising: The cooling storage device according to claim 3, wherein a communication unit is provided in each storage, and the control signal and the like can be communicated between the communication units. The cooling storage device according to any one of claims 2 to 4, wherein the cooling load is determined based on an output of the temperature sensor.

Images