JP2000088408A - Monitoring apparatus for low temperature tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sense trouble in connection with a temperature rise in a low temperature tank by sensing an operating state of a compressor according to a state of a current flowing through an electric circuit for supplying a driving power to the compressor, and generating an alarm when the operating state corresponds to one of setting conditions. SOLUTION: The monitoring apparatus 21 is connected to both sides of a motor of an electric circuit 13 of a low temperature side refrigerator 1 via a power source circuit 22 and an applying voltage circuit 23. The circuit 22 is connected to a power source display lamp 26 and an electronic controller 23 via a transforming and rectifying circuit 24 and a DC stabilized power source 25. The circuit 23 is connected to an electronic controller 28 via a rectifying circuit 27. The controller 28 senses an operating state of a compressor 2 according to a state of a current flowing through the circuit 13 for supplying the power to the compressor 2, decides whether the operating state corresponds to setting conditions or not, and generates an alarm by an alarm sound generator 30 when the state corresponds to one of the conditions according to its decision.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring device for detecting and reporting an abnormality of a refrigerator in a low-temperature tank for freezing and preserving a sample in medicine and physics and chemistry.

[0002]

2. Description of the Related Art In the preservation of samples such as cells, fungi, tissues, and specimens in medical and physical chemistry, cryopreservation at a low temperature of about -40.degree. C. or an ultra-low temperature of -80.degree.

When a sample is stored at such a low or very low temperature for a long period of time, in order to maintain a stable state without deteriorating the sample, it is necessary to maintain the temperature in the bath within a predetermined set temperature range. It is necessary to provide a safety measure to issue an alarm when the temperature inside the bath exceeds the allowable range of the set temperature because the refrigerator stops or does not operate normally due to power failure or failure. .

[0004]

According to the above-described safety measures for detecting the temperature in the bath and issuing an alarm, if the allowable range is set to a large value, it may take a long time from receiving the alarm to taking measures. There is a concern about sample deterioration due to temperature rise. Conversely, if the allowable range is set to a small value, there is a concern that a change in the temperature inside the bath due to the loading and unloading of the sample will cause an alarm, and the device will react to a temporary temperature change due to a power failure or failure.

[0005] Therefore, it is extremely difficult to make it possible to cope with deterioration of the sample due to a rise in temperature and not to react to a temporary temperature change. In addition, the fact that the refrigerator has stopped due to a power failure or a failure can be known from an increase in the temperature in the bath, but other than that, it cannot be known about a trouble leading to a rise in the temperature in the bath.

According to the present invention, when the temperature in the low-temperature tank changes from a set temperature beyond an allowable range, this is not known until the temperature of the low-temperature tank is increased. In addition to the problem that there is a concern that a warning will be issued even for a temporary temperature change that is not caused by a power failure or a failure, and in addition to these problems, currently the temperature in the bath is not changed beyond the allowable range, which will eventually be the cause This was done to solve the inconvenience of not being able to know about the trouble.

[0007]

That is, the present invention detects an operating state of a compressor of a refrigerator for cooling the inside of a tank, and issues an alarm before the temperature in the tank rises beyond an allowable range. Means for detecting the operating state of the compressor according to the state of the current flowing through the electric circuit that supplies the driving power to the compressor, and the operating state corresponds to the set condition. Means for determining whether or not to perform, and means for issuing an alarm when one of the set conditions is met.

In the present invention, when the compressor is stopped for a predetermined period of time after a predetermined period of time after the compressor is stopped, and when the compressor is repeatedly operated for a predetermined period of time a plurality of times with a short stop period, the compressor is stopped for a predetermined period of time. During continuous operation, there were three.

When the temperature in the bath is set, the refrigerator operates so that the set temperature is maintained, and the compressor repeatedly starts and stops almost regularly. When a trouble such as a power outage, disconnection, or failure occurs, the compressor remains stopped for a long time and the temperature in the tank rises. Therefore, it is one of the conditions for issuing an alarm that a certain time elapses while the compressor is stopped. Specifically, it is preferable that the time is 45 minutes to 1 hour. By issuing an alarm after the elapse of the time, an auxiliary power supply or an auxiliary cooling is performed before the temperature in the chamber rises beyond the allowable range of the set temperature. By switching to the device, it is possible to wait for the restoration of power transmission or repair a disconnection or failure without fear of altering the sample.

Next, the performance of the refrigerator itself is deteriorated due to deterioration of the compressor over time, reduction due to leakage of the refrigerant, clogging of the filter, etc., frequent opening and closing of the tank door, leaving the door closed incompletely, When a trouble such as a rise in temperature occurs, the compressor is repeatedly operated for a long time with a short stoppage time in order to maintain the inside of the tank at the set temperature.

If this is left as it is, it will stop the function of the refrigerator and increase the temperature in the tank. Therefore, another condition for issuing an alarm is to repeat the operation of the compressor for a predetermined time or more with a short stop time. It is preferable that the time and the number of repetitions for issuing the alarm be specifically when the continuous operation for 2 hours or more or the continuous operation for 3 hours or more is repeated three times, and when the condition is met. Recover the function by repairing and maintaining the refrigerator by issuing an alarm.Restrict the opening and closing of the tank door, completely close the door, and adjust the air conditioning equipment at the installation site to return the sample to a normal state without worrying about deterioration of the sample. Can be.

Further, when troubles such as a significant decrease in the performance of the refrigerator due to leakage of the refrigerant and a failure of the control parts occur, the compressor is stopped in order to maintain the inside of the tank at the set temperature or due to uncontrollable runaway. Continuous operation may be performed without the need.

If this is left as it is, it will stop the function of the refrigerator and increase the temperature in the tank. Therefore, another condition for issuing a warning that the compressor should be continuously operated for a certain period of time or longer was set. The continuous operation time for issuing an alarm is specifically 10
It is preferable to set the time to about a time, and when the condition is satisfied, the sample can be returned to a normal state without worrying about deterioration of the sample by repairing the refrigerator, replacing control parts, and the like.

Further, the present invention includes, as setting conditions for issuing an alarm, the above three setting conditions which are determined based on the intermittent state of the current, when the current value of the electric circuit exceeds a normal value for a predetermined time.
To four.

When the motor for driving the compressor is operating normally, the current flowing through the electric circuit maintains a constant value, but when the motor is deteriorated or the power supply voltage drops, the current higher than the normal value is increased. If this state continues for a long time, the motor may seize. Therefore, one of the conditions for issuing an alarm is that the current value exceeds the normal value for a certain period of time. Specifically, it is preferable that this time is about 5 minutes from the time when the specified value set to a value that is higher than the normal value but considered to be safe is exceeded, and an alarm is issued after the elapse of this time. Repairing or replacing the motor without worrying about false alarms due to the starting current, or restricting or stopping the operation of the electric load device, etc., to prevent the rise in the temperature of the chamber due to the stoppage of the seizure of the motor earlier than the first setting condition can do.

In addition, the present invention comprises a computer for receiving and recording alarms electrically. This computer records the date and time and the details of the trouble every time a low-temperature alarm is generated. By displaying the history on a display or printing it on paper, it can be useful for materials such as periodic inspection and life judgment. it can.

Therefore, according to the present invention, it is possible to detect in advance the temperature rise due to various causes, to perform a recovery process earlier than to change the quality of the sample, to maintain the temperature in the tank within a predetermined set temperature range, Can be achieved in a stable state for a long period of time.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to detection of an abnormality in a low-temperature tank using a binary refrigerator will be described with reference to the drawings. The multi-stage refrigerator is widely known as a refrigeration system for ultra-low temperature. In the illustrated two-way refrigerator, the condenser 3 of the low-temperature refrigerator 1 is cooled by the evaporator 12 of the high-temperature refrigerator 7, A relatively high-pressure refrigerant is used in a cycle including the compressor 2, the condenser 3, the receiver 4, the expansion valve 5, and the evaporator 6 of the side refrigerator 1, and the compressor 8 of the high temperature refrigerator 7 It is generally known that a relatively low-pressure refrigerant is used in a cycle including the vessel 9, the liquid receiver 10, the expansion valve 11, and the evaporator 12.

Electric circuits 13 and 16 for supplying driving power to electric motors for driving the compressors 2 and 8 of the two refrigerators 1 and 7 are connected in parallel to an AC power supply circuit 19, and start relays 14 and 17, respectively. Overload relays 15 and 18 are provided.

In such a binary refrigerator, the low-temperature refrigerator 1 exhibits a predetermined cooling capacity only when the high-temperature refrigerator 7 is operating normally. By monitoring the operating state of the two refrigerators 1, 7 can be detected. Therefore, in the illustrated embodiment, the monitoring device 21 of the present invention is connected to the low-
The electric circuit 13 was connected to both sides of the electric motor by a power supply circuit 22 and an applied voltage circuit 23, respectively.

The power supply circuit 22 is connected to a power indicator lamp 26 and an electronic control unit 28 via a transformer / rectifier circuit 24 and a stabilized DC power supply 25. The applied voltage circuit 23 is connected to an electronic control unit 28 via a rectifier circuit 27. It is connected. An operation indicator 29, an alarm sound generator (buzzer) 30, an alarm signal transmitter 31, and a reset button 32 are connected to the electronic control unit 28.

The electronic control unit 28 includes a CPU, RAM, RO
This is a widely known microcomputer including an M and an input / output circuit, and incorporates three or four setting conditions and a determination function thereof in the present invention. Therefore, the electronic control unit 28 has both means for detecting the operating state of the compressor 2 of the present invention and means for determining whether or not the operating state satisfies the set condition. Further, the operation indicator light 29, the alarm sound generator 30, and the alarm signal transmitter 31 in addition to these constitute a means for issuing an alarm in the present invention.

The compressor 2 on the low temperature side has a power failure, a failure or an electric circuit 13.
When the compressor 8 on the high temperature side stops for the same reason, the overload relay 15 operates and stops. This trouble corresponds to the first set condition that the compressor stops and a certain period of time elapses, and the operation indicator light 29 turns off and the alarm generator 30
Emits an alarm sound.

Next, when the inside temperature of the tank is going to rise due to the deterioration of the performance of each of the refrigerators 1 and 7, the opening / closing state of the tank door, the ambient temperature, etc. The operation time per operation is long and the stop time is short, and the interior of the refrigerator is maintained at the set temperature. At this time, when the second set condition that the compressor repeats the operation for a predetermined time or more a plurality of times with a short stop time is met, the operation indicator light 29 blinks and the alarm sound generator 30 emits the alarm sound. Emits.

Further, when the performance of one or both of the two refrigerating machines 1 and 7 is significantly reduced, or when these control parts are out of order, the compressor 2 on the low temperature side keeps the internal temperature of the refrigerator. Alternatively, continuous operation is performed without stopping due to uncontrollable runaway. This trouble corresponds to the third set condition that the compressor operates continuously for a certain period of time.
Emits an alarm sound.

The above three setting conditions are all assumed to be troubles that do not depend on the electric motor. However, when the electric motor or the refrigerator circuit is deteriorated, or when the power supply voltage drops due to heavy use of electric load equipment, Then, a current higher than a normal value flows through the motor. Trouble that this current flows continuously for a certain period of time beyond the specified value considered safe,
This corresponds to the fourth setting condition that the current value of the electric circuit exceeds the normal value for a certain period of time, and the alarm sound generator 30 emits an alarm sound while the operation indicator lamp 29 is on.

When the occurrence of a trouble is recognized by an alarm, necessary recovery measures are taken, and when this is completed, the reset button 32 is pressed to resume monitoring. According to the present embodiment, the blinking state of the operation indicator lamp 29 that blinks in response to the operation / stop of the refrigerator 2 differs depending on the three setting conditions, so that the cause of the trouble can be considerably limited, and appropriate recovery can be performed. The treatment can be performed quickly, and it is easy to measure the safety of the sample.

Here, in addition to the monitoring device 21 being provided inside or outside the low-temperature tank, the power supply circuit 22 and the applied voltage circuit 23 are extended and installed at one place to centrally control many units. Can also.

However, according to the present invention, the monitoring device 21 is provided inside or outside the low-temperature tank so that an abnormality can be known at a short distance.
An external alarm 35 including an alarm sound generator 37 is provided remotely, or an alarm signal transmitter 31 is provided to enable transmission to a display pager or a telephone.

The external alarm 35 issues an alarm at the same time as the operation indicator 29 and the alarm sound generator 30 by an extended transmission line 38 extending from the DC stabilizing circuit 25 and the electronic control unit 28. The alarm signal transmitter 31 is connected to the telephone line 40, and sends an alarm from the central office 41 to the display pager 42 and the telephone 43 to notify the user of what kind of trouble has occurred in which low-temperature tank by text or voice. .

By providing such an external alarm device 35 and an alarm signal transmitter 31, the monitoring posture of the low-temperature tank can be made thorough, and an accident due to oversight or hearing loss can be eliminated.

Further, in the present invention, a computer 45 is provided for storing the date and time and the content of the trouble every time a low-temperature tank alarm is generated, which is connected to the electronic control unit 28 and the external transmission line 4.
6 connected. A general personal computer is used as the computer 45. The computer 45 is connected to a large number of low-temperature tanks, stores the troubles that have occurred in the past, displays the history of each low-temperature tank on a display, or prints out the history on paper and outputs it. Thereby, it can be used as a material for performing a periodic inspection and a life judgment for replacement of parts or the whole.

[0033]

As described above, according to the present invention, not only the trouble directly causing the rise in the temperature of the bath, but also the trouble which will eventually lead to the rise in the temperature of the bath is detected, and the quality of the cryopreserved sample is changed. The temperature rise can be detected in advance and appropriate recovery measures can be taken, and the safety of the low-temperature tank is excellent.

[Brief description of the drawings]

FIG. 1 is a layout diagram showing an embodiment of the present invention.

[Explanation of symbols]

1 low temperature refrigerator, 2 compressor, 13 electric circuit, 2
1 monitoring device, 28 electronic control device, 29 operation indicator light, 30 alarm sound generator, 31 alarm signal transmitter,
35 external alarm, 42 display pager, 43 telephone, 45 computer,

Claims (7)

[Claims] A means for detecting an operation state of the compressor based on a state of a current flowing through an electric circuit for supplying drive power to a compressor of a refrigerator for cooling the inside of the tank; and determining whether the operation state satisfies a set condition. Means for determining whether or not, and means for issuing an alarm when one of the set conditions is met,
The set conditions are (1) a fixed time elapses after the compressor stops, (2) the compressor repeats the operation for a predetermined time or more a plurality of times with a short stop time, and (3) the compressor operates continuously for a certain time. A monitoring device for a low-temperature tank. 2. A means for detecting an operation state of the compressor based on a current flowing through an electric circuit for supplying drive power to a compressor of a refrigerator for cooling the inside of the tank, and determining whether the operation state satisfies a set condition. Means for determining whether or not, and means for issuing an alarm when one of the set conditions is met,
The set conditions are (1) a fixed time elapses after the compressor stops, (2) the compressor repeats the operation for a predetermined time or more a plurality of times with a short stop time, and (3) the compressor operates continuously for a certain time. (4) The low-temperature chamber monitoring device, wherein the current value of the electric circuit exceeds a normal value for a certain period of time. 3. The low-temperature tank monitoring device according to claim 1, further comprising a computer that electrically receives and records the alarm. 4. The electronic control unit according to claim 1, wherein the means for detecting the operating state of the compressor and the means for determining whether the operating state meets a set condition are electronic control units. Monitoring device for low temperature tank. 5. The two sets of means for issuing the alarm are provided in the vicinity of the means for detecting the operating state and the means for determining whether or not the condition is satisfied, and those provided remotely. The monitoring device for a low-temperature tank according to claim 1, 2, or 3. 6. The warning device according to claim 1, wherein the means for issuing an alarm includes an operation indicator light that flashes in response to the operation / stop of the compressor, and an alarm sound generator that emits an alarm sound when one of the set conditions is satisfied. The low-temperature tank monitoring device according to claim 1, 2 or 3. 7. An operation indicator for blinking in response to the operation / stop of the compressor, an alarm sound generator for emitting an alarm sound when one of the set conditions is met, 4. The low-temperature chamber monitoring device according to claim 1, further comprising a display pager connected to a telephone line and an alarm signal transmitter for transmitting the alarm to a telephone.