JPS589163Y2 - Constant temperature warehouse - Google Patents

Description

[Detailed description of the invention] This invention is a refrigerator or
The present invention relates to a battery charging control circuit that operates an auxiliary cooling device for a so-called constant temperature warehouse, such as an ultra-low temperature chamber that is maintained at a temperature of 80°C.

Generally commercially available ultra-low temperature tanks at -80°C use a dual refrigeration system, but since two refrigeration cycles are loaded, the number of parts is large and the failure rate is high.

For example, if there is a gas leak somewhere in the high-temperature side refrigeration cycle, the condenser of the low-temperature side refrigeration cycle will not be cooled, so the inside of the refrigerator cannot be cooled down to -80°C.

Furthermore, in the event of a power outage or a malfunction of the internal temperature controller, the refrigeration system becomes inoperable, causing the internal temperature to rise gradually.

Abnormal rises in temperature inside the refrigerator due to these unexpected accidents are undesirable because they cause the stored items (for example, frozen blood, etc.) to spoil and become unusable.

To prevent this, in addition to the refrigeration system that cools the inside of the refrigerator, for example, an auxiliary cooling device that adds a liquefied carbon dioxide gas cylinder and evaporates the liquefied carbon dioxide inside the refrigerator to suppress the abnormal temperature rise inside the refrigerator for a certain period of time is installed. It is being considered to establish one.

The present invention extends the batch no discharge time for operating this auxiliary cooling device, and will be described in detail below with reference to the drawings.

Reference numeral 1 denotes an ultra-low temperature chamber cooled by a dual refrigeration system, and the inside of the chamber is cooled to an ultra-low temperature of -80°C or the like.

2 is a door that closes the upper opening; 3 is a pipe that has one end opened in the refrigerator interior 1A; the other end is connected to a liquefied carbon dioxide gas cylinder 4.

Reference numeral 5 denotes a solenoid valve provided in the middle of the pipe 3, and when the solenoid valve 5 is opened, liquefied carbon dioxide gas is supplied to the interior 1A of the refrigerator and is cooled.

FIG. 2 is a block diagram of the operation process of the auxiliary cooling device, in which the alarm signal generating section 6 is operated at an upper limit temperature (
For example, when the set temperature is 180°C, the upper limit temperature is set to 175°C, etc.) and a signal is generated when the internal temperature rises.

The auxiliary cooling device operating section 7 and the alarm section 8 are operated in response to signals from the above-mentioned alarm signal generating section 6, and the auxiliary cooling device operating section 7 operates the solenoid valve 5, and the alarm section 8 operates the internal 1A of the refrigerator. An alarm is issued to notify the user of an abnormal increase in the amount of water.

FIG. 3 is an implementation circuit diagram of the auxiliary cooling device operating section 7,
The transformer 9 generates, for example, 24V on the secondary side.

The diodes 10, 10', 10'', and 10'' are a rectifier circuit combined in a bridge shape for full-wave rectification, and the battery 11 has a DC power supply, that is, a full-wave rectified current, which has passed through this rectifier circuit, and is limited by the resistor 12. It is designed to be charged as a minute current.

Bachno 11, for example, consists of 12 lead-acid batteries 2 connected in series, each of which has an overcharge prevention contact 11A, and can be charged with the aforementioned minute current (a current 0.05 times the normal rated discharge current). When it is finished, the contact 11A is O.
Consideration has been taken to turn the battery FF and stop further charging.

13 is a fuse, 14 is a test switch, 15 is a power supply isolation relay, and 16 is an auxiliary cooling device stop switch.

Contact 15B of power supply isolation relay 15 has a resistance of 1 when turned ON.
2 are connected to short-circuit them.

The input terminals 17 and 17' are connected to both ends of the test switch 14, and are output terminals 1 from which an output for operating the alarm unit 8 can be taken out from the contact 15C of the power isolation relay 15.
8.18' is provided.

FIG. 4 is an implementation circuit diagram of the alarm unit 8, in which the secondary side of the transformer 19 generates, for example, 2.4V, and the diode 2
0, resistance 21. An alarm battery 23 such as a Licadonica battery is charged by the series circuit of the fuse 22.

24 is an alarm stop switch, 25 is a stop relay, 26
27 is an alarm lamp, 27 is an alarm buzzer, 28 is a buzzer stop switch, and 29 is a test switch.

Input terminals 30, 30' are provided at both ends of the test switch 29, and the outputs from the output terminals 18, 18' in FIG. 3 are connected thereto.

The coil 25L of the power failure relay 25 is connected to the transformer 1.
When the AC power supply is normal, current flows through the coil 25L, turning off the contact 25A and constantly stopping the alarm lamp 26 and alarm buzzer 27.

Next, the operation of these circuits will be explained.

Power is applied to the dual refrigeration system, and the temperature inside the refrigerator ranges from -78℃ to 80℃.
In this state, the battery 11 is charged with a minute current through the resistor 12, the overcharge prevention contact 11A, and the fuse 13, and the overcharge prevention contact 11A is turned off when it is fully charged.

Furthermore, the alarm battery 23 also has a resistor 21. It is charged via the fuse 22 and is in a fully charged state.

If the temperature regulator for controlling the temperature inside the refrigerator fails in this state, the temperature inside the refrigerator gradually rises and an alarm sensor (not shown) turns on its contact at an upper limit temperature of, for example, -75°C.

Therefore, the input terminals 17 and 17' are short-circuited, and the coil 15L of the power isolation relay 15 is connected to the battery 11.
A voltage of 24V is applied to each contact 15A, 15B.

15C turns on.

By turning on contact 15A, auxiliary cooling device stop switch 1 is turned on.
6 (this switch is turned ON to operate the auxiliary cooling device), the 24V voltage of the battery 11 is applied to the solenoid valve coil 5', the solenoid valve 5 is opened, and the liquefied carbon dioxide gas flows into the refrigerator at 1A. It is injected and removes the heat of vaporization caused by evaporation to suppress the rise in temperature inside the refrigerator.

On the other hand, when the contact 15C is turned on, the input terminals 30 and 30' are short-circuited, and the voltage of 2.4 cm of the alarm battery 23 lights up the alarm lamp 26 and sounds the alarm buzzer 27, causing the user to increase the temperature inside the refrigerator. Informs you that some kind of malfunction has occurred.

Also, when the battery 11 is discharged by the operation of the coil 15L of the power supply isolation relay 15 and the solenoid valve coil 5' and the overcharge prevention contact 11A is turned ON, since the contact 15B is ON, both coils 15L and 5' are Both contacts 15 B
, 11 A, a full-wave rectified current, actually a straight DC current that is discharged from the battery 11 to smooth the full-wave rectified current, flows from the battery 11 by the full-wave rectified current. The discharge current is reduced and the auxiliary cooling device can be operated for a long time.

Furthermore, a charging current is flowing through the battery 11 at this time,
The aforementioned long-time operation (long-time discharge) is ensured.

This state is illustrated in Figure 5, where the vertical axis is the current and the horizontal axis is the time t.The DC power supply with the diameter of the rectifier circuit is the curve shown in iA, and the coil 15L of the power supply separation relay 15 and the solenoid valve If the magnitude of the current flowing through the coil 5 is L, then 11
- The larger power supply portion X is used to charge the battery 11, and the smaller current portion Y than iL is replenished with this charge by discharging, so that the battery 11 plays the role of a smoothing element.

If X and Y are the same size depending on the size of iL, the battery 11 will not be discharged at all, if X is larger than Y, it will be gradually charged, and conversely, if X is smaller than Y, the battery 11 will gradually be discharged. It will be done.

In any case, since the AC power source is used, the discharge time of the battery 11 becomes long, and the auxiliary cooling device can continue to operate for a long time.

In addition, since liquefied carbon dioxide gas vaporizes at 178° C., the interior 1A of the refrigerator is cooled to this temperature.

In this case, if the alarm sensor is to be turned off at -77°C, the input terminal 17.17'
The short circuit is removed and the injection of liquefied carbon dioxide is stopped, and the alarm lamp 26 and alarm buzzer 27 are also stopped and the temperature rises to -75℃ again.
These will be activated when the temperature rises to .

If you want to stop the alarm buzzer 27 when you confirm it, you can turn off the buzzer stop switch 28.

In the above, we talked about an abnormality in the internal temperature controller when there was no abnormality in the power supply, but next we will discuss what happens when there is a power outage.

When the power went out, the temperature inside the 1A refrigerator gradually rose to -75℃.
When the alarm sensor reaches 17., the contact of the alarm sensor turns ON and the input terminal 17.
17' is short-circuited, the electromagnetic valve coil 5' is energized by the battery 11 as described above, the electromagnetic valve 5 is opened, and liquefied carbon dioxide gas is injected into the refrigerator interior 1A, thereby suppressing a rise in the temperature inside the refrigerator.

On the other hand, since the power failure relay 25 becomes inoperable at the same time as the power failure, its contact 25A is turned on and the alarm lamp 26 and alarm buzzer 2
7 operates and notifies the user of this.

(This operation is performed earlier than the above-mentioned temperature rise inside the refrigerator.

) During the power outage, the auxiliary cooling device is operated by the battery 11 to suppress the temperature rise inside the refrigerator, and when the power returns to normal, the dual refrigeration system is operated again to maintain the temperature inside the refrigerator at a constant level.

In addition, the test switch 14.29 is for these auxiliary cooling devices,
This is to check the operation of the alarm, and can set a pseudo abnormality (i.e., the aforementioned temperature controller failure or power outage).

In this embodiment, liquefied carbon dioxide gas was used for auxiliary cooling, but other materials such as liquefied nitrogen gas may be used instead.

As mentioned above, this invention uses a constant-temperature refrigerator that uses a refrigeration system to cool the inside of the refrigerator and activates the auxiliary cooling device when the temperature inside the refrigerator rises abnormally above the set temperature. It is charged by limiting the charging current with a resistor, and when the temperature rises abnormally due to a power outage, it is discharged from the battery to operate the auxiliary cooling device, and when there is no abnormality in the power supply, the auxiliary cooling device is operated by the power supply. It is something.

Therefore, when the temperature inside the refrigerator rises abnormally, the auxiliary cooling system can be operated to suppress this temperature rise, and the stored items can be stored temporarily, so they can be used between two times or moved to another constant temperature storage. This is something that can be addressed.

Furthermore, when operating the auxiliary cooling device when there is no abnormality in the AC power supply, we minimize the discharge from the battery and operate it with the AC power supply (although we have actually changed it to DC). Since the time can be extended, there is no need to provide a battery with a large discharge capacity, and since the battery is used as a smoothing element, a separate smoothing capacitor or the like is not required.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view of the constant temperature storage according to the present invention, Fig. 2 is a block diagram of the operation process of the auxiliary cooling device, Fig. 3 is an electric circuit diagram,
FIG. 4 is an electric circuit diagram of the alarm unit, and FIG. 5 is a characteristic diagram of charging and discharging states of the battery when there is no abnormality in the AC power source. 1... Cryogenic tank, 4... Liquefied carbon dioxide gas cylinder, 5... Solenoid valve, 11... Battery, 12... Resistor.

Claims (1)

[Scope of utility model registration request] Controls the supply of liquefied gas from the auxiliary cooling device to the inside of the refrigerator in a constant-temperature warehouse in which the interior of the refrigerator is cooled by a refrigeration device and the auxiliary cooling device is activated when the temperature inside the refrigerator rises abnormally above a set temperature. The battery that operates the solenoid valve is normally charged with a resistor that limits the charging current, and when the temperature rises abnormally due to a power outage, the battery is charged based on the operation of a sensor that operates at the increased upper limit temperature. The solenoid valve is actuated in the liquefied gas supply state by the supplied voltage, and when there is no abnormality in the power source, the solenoid valve is actuated by the power source based on the operation of the sensor. Constant temperature storage.