JPH07120128A - Controller for cooling storage box - Google Patents

Abstract

PURPOSE:To improve pull-down characteristics of a temperature in a storage chamber immediately after installation, defrosting, etc. CONSTITUTION:Cold gas heat exchanged with a cooler is forcibly circulated into a storage chamber by a blower 2. A speed regulator l for regulating number of revolutions of the blower 2 by a thermostat 10 is provided. The thermostat 10 closes a relay switch 6 when a temperature in the chamber is a predetermined high temperature or higher to short-circuit both ends of a variable resistor 4, outputs an input power 5 to the blower 2 as it is to perform a high speed operation. If the temperature in the chamber is lower than it, it opens the switch 6 to outputs an output voltage of an arbitrary resistance value of the resistor 4 to the blower 2, thereby conducting an ordinary low-speed operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling storage control device for storing articles such as food while cooling them.

[0002]

2. Description of the Related Art Conventionally, in such a cold storage, for example, a prefabricated refrigerator, a cooler is installed in a storage room surrounded by a heat insulating panel, and cool air that has exchanged heat with the cooler is forcedly circulated by a blower so that the storage room is cooled. Is cooling. In this case, an upper limit value and a lower limit value are set above and below the set temperature of the storage chamber, and the compressor is operated when the temperature inside the storage chamber reaches the upper limit value by a thermostat that operates based on the temperature inside the storage chamber. Or cooling operation is performed by supplying refrigerant to the cooler by opening a refrigerant control valve or the like, and when the temperature in the storage chamber reaches the lower limit value, the compressor is stopped, or refrigerant control is performed. The refrigerant supply to the cooler is stopped by closing the valve or the like.

A blower circulates cold air that has exchanged heat with a cooler in the storage chamber and agitates the cold air in the storage chamber to maintain a uniform temperature in the entire storage chamber. Was operating at a constant speed regardless of the temperature in the storage room.

[0004]

As described above, since the conventional blower is operated at the same number of revolutions regardless of the temperature in the storage chamber, it is set at the time of so-called pull-down immediately after the cooling storage is installed or immediately after defrosting. It takes a long time to reduce the temperature in the storage chamber from a temperature extremely higher than the temperature to the vicinity of the set temperature, and there is a problem that spoilage of the stored food or the like is promoted.

This inconvenience becomes remarkable especially when the rotation speed of the blower during the normal cooling operation is suppressed so as to suppress the discoloration or deterioration of the food surface due to excessive cold air agitation. The present invention has been made to solve the above-mentioned conventional technical problems, and an object of the present invention is to provide a control device for a cooling storage with improved pull-down characteristics of the temperature of the storage chamber immediately after installation or immediately after defrosting. And

[0006]

The control device of the present invention is applied to a cooling storage box in which cold air that has exchanged heat with a cooler is forcibly circulated in a storage room by a blower, and a temperature detecting means for detecting the temperature in the storage room. And a speed adjusting means for adjusting the number of rotations of the blower are provided, and the speed adjusting means is based on the temperature detecting means,
When the temperature in the storage chamber is equal to or higher than a predetermined high temperature, the rotation speed of the blower is set to high speed operation, and when it is lower than that, the rotation speed of the blower is set to normal low speed operation.

[0007]

According to the cooling storage control device of the present invention, the speed adjusting means is based on the temperature detecting means, and when the temperature in the storage chamber is lower than a predetermined high temperature, the rotation speed of the blower is set to a normal low speed operation. Therefore, while maintaining the minimum cold air circulation in the storage chamber, it is possible to prevent excessive cold air agitation in the storage chamber and suppress the occurrence of damage such as discoloration of stored articles (food etc.).

When the temperature in the storage chamber is equal to or higher than a predetermined high temperature, the speed adjusting means operates the rotation speed of the blower at a high speed, so that a large amount of cold air that has exchanged heat with the cooler is circulated in the storage chamber. The temperature can be lowered rapidly. Therefore, it becomes possible to quickly lower the temperature of the storage room immediately after the cooling storage is installed or when the cooler is defrosted after defrosting, etc., and it is possible to prevent the occurrence of putrefaction of the stored food in advance. Become.

[0009]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is an electric circuit diagram of a speed adjusting device 1 portion as a speed adjusting means of a control device C of a cooling storage according to the present invention, and FIG. 2 is an electric circuit diagram of a temperature controlling device 20 part of the controller C. The controller C is provided in a prefabricated refrigerator (not shown) as a cooling storage configured by assembling heat insulating panels, for example.

In a storage chamber (not shown) of the prefabricated refrigerator, a cooler (not shown) is also installed. The cooler is discharged from a compressor of a cooling device (not shown) and is condensed by a condenser. And a pressure reducer (expansion valve, etc.)
The refrigerant reduced in pressure is supplied through, for example, the refrigerant control valve 23. The cool air that has exchanged heat with the cooler is forcibly circulated in the storage chamber by the blower 2 including a three-phase AC motor, and is configured to cool articles such as fresh meat and fresh fish stored in the storage chamber.

Next, referring to FIGS. 1 and 2, the controller C
The speed control device 1 for adjusting the rotation speed of the blower 2 is composed of a waveform control circuit 3, a variable resistor 4, a relay switch 6 and a relay coil 11, and is provided on the input side of the waveform control circuit 3. Are connected to terminals TR, TS, and TT, and a commercial power source (for example, AC three-phase 200 V) 5 is connected.
The relay coil 11 is connected between the terminals T3 and T3, and the terminals T3 and T3 are external thermostats 10 as temperature detecting means for detecting the temperature in the storage chamber (not shown).
Is connected to the commercial power source 5 via. The blower 2 is connected to the output side of the waveform control circuit 3 via terminals TU, TV, and TW. The variable resistor 4 and the relay switch 6 are connected to the waveform control circuit 3 in parallel with each other.

The waveform control circuit 3 controls the input AC waveform of the commercial power source 5 (for example, a sawtooth wave or an intermittent waveform to reduce the pressure), and outputs it according to the resistance value of the connected variable resistor 4. When the resistance value is large, the output voltage decreases and the rotation speed of the blower 2 slows down. Conversely, when the resistance value is small, the output voltage rises and the blower 2 The rotation speed is increased. Also,
The relay switch 6 is closed by energizing the relay coil 11 and shorting both ends of the variable resistor 4 so that the resistance value is 0.
To work. The waveform control circuit 3 is a variable resistor 4
When both ends of the are short-circuited by the relay switch 6, the AC waveform is not controlled and the input power source (waveform) 5 is directly output to the output terminals TU, TV and TW. Further, the thermostat 10 is installed in the storage chamber of the cooling storage, and closes the contact at a predetermined high temperature (for example, + 15 ° C.) or higher sufficiently higher than the set temperature of the storage chamber described later, and opens the contact at a temperature lower than that.

On the other hand, in FIG. 2, the refrigerant control valve 23 is connected to the terminals T4 and T4 of the temperature control device 20 via a thermostat 21 which opens and closes the contacts based on the set temperature in the storage chamber (not shown). And each terminal T
4, T4 are commercial power sources (not shown) (for example, single-phase AC 100
Bolts) 22 respectively. This thermostat 21 is also installed in the storage room of the cooling storage, and opens and closes the contacts between the upper limit value (for example + 5 ° C.) and the lower limit value (for example 0 ° C.) set above and below the set temperature (for example + 3 ° C.) of the storage room. . When the thermostat 21 closes the contact, the refrigerant control valve 23 is energized, and the refrigerant control valve 23 opens to supply the refrigerant to the cooler, thereby executing the cooling operation. Then, when the thermostat 21 opens the contact, the refrigerant control valve 23 is de-energized, the refrigerant control valve 23 is closed to stop the refrigerant supply to the cooler, and the non-cooling operation is performed.

The operation of the above configuration will be described below. First,
The temperature inside the storage is, for example, + 3 ° C with the thermostat 21.
The thermostat 10 is set to +1
It is assumed that 5 ° C. is set and the resistance value of the variable resistor 4 is set to rotate at 30% of the rotation speed of the blower 2 at full speed. For example, when the power switch of the cooling device provided in the prefabricated refrigerator (not shown) is turned on, the control device C
The commercial power supply 5 is supplied to the speed control device 1 and the commercial power supply 22 is supplied to the temperature control device 20. Now, assuming that the cooling storage is immediately after being installed, the temperature in the storage chamber is higher than the high temperature (+ 15 ° C.). Therefore, the thermostat 10 closes the contact, and the thermostat 21 also closes the contact because it is higher than the upper limit value (5 ° C.). As a result, the refrigerant control valve 23 is energized and opened, and the compressor (not shown) starts its operation to supply the refrigerant to the cooler to start the cooling operation.

Since the relay coil 11 is also energized when the thermostat 10 is closed, the relay switch 6 of the speed regulator 1 is closed, the variable resistor 4 is short-circuited, and the waveform control circuit 3 of the power source 5 is closed. The waveform is directly output to the blower 2 without being controlled. As a result, the blower 2 rotates at a high speed (100%) and forcibly circulates a large amount of cold air that has exchanged heat with the cooler in the storage chamber to rapidly cool the storage chamber.

When the temperature inside the storage chamber is rapidly cooled and the temperature becomes lower than the set value (+ 15 ° C.), the thermostat 10 opens the contact. With this, the relay coil 1
Since 1 is de-energized and the relay switch 6 opens the contact, the blower 2 is operated at the normal (30% of rated) rotation speed set by the variable resistor 4 of the speed control device 1 thereafter.

Further, when the inside of the storage chamber is cooled and reaches the lower limit value (0 ° C.) set by the thermostat 21, the thermostat 21 opens the contact to de-energize the refrigerant control valve 23 and closes it. Is also stopped, and the supply of the refrigerant to the cooler is stopped to start non-cooling operation. After that, when the temperature in the storage chamber rises and reaches the upper limit value (+ 5 ° C.), the thermostat 21 closes the contact again and opens the refrigerant control valve 23 to restart the cooling operation. As a result, the inside of the storage chamber is maintained at the set temperature of + 3 ° C. on average. Further, at this time, since the temperature in the storage chamber is lower than the high temperature (15 ° C.), the blower 2 performs a normal low speed operation (30%) to circulate the cool air that has exchanged heat with the cooler relatively gently in the storage chamber.

When the temperature inside the storage chamber rises abnormally to the above + 15 ° C. or above due to defrosting of the cooler or a large amount of heat load being applied to the storage chamber, the thermostat 10 will cause the contact to come into contact. Since it is closed, the relay coil 11 is energized and the relay switch 6 also closes the contact. As a result, both ends of the variable resistor 4 are short-circuited, and the speed adjusting device 1
As described above, the input power source (AC) 5 is output as it is without being controlled, and the blower 2 is rotated at a high speed of 100%. As a result, a large amount of cold air is supplied to the storage chamber, and the temperature is rapidly lowered.

As described above, in the present invention, since the waveform control circuit 3 of the speed control device 1 normally operates the blower 2 at a low speed (30%), the fan is housed while maintaining the minimum cold air agitation. It is possible to prevent discoloration of food such as meat and fresh fish. When the temperature in the storage chamber is + 15 ° C. or higher, the waveform control circuit 3 of the speed regulator 1 sets the rotation speed of the blower 2 to high speed (100%), so that the storage chamber can be rapidly cooled during pull-down. As a result, the occurrence of food spoilage can be suppressed.

The various numerical values shown in the embodiments are not limited to these values, and may be set appropriately according to the capacity of the stored articles and the cooling device. Further, the present invention is effective not only for food such as meat but also for storage of other vegetables or fruits. Further, although the thermostats 10 and 21 are used as the means for detecting the temperature in the storage chamber, the same effect can be obtained even if the temperature in the storage chamber is detected by the electronic detection means such as a thermistor and the rotation speed of the blower 2 is controlled. Can be demonstrated. Further, although the commercial power source 5 of the control device C is an AC three-phase 200 volt, it may be driven by a single-phase 100 volt power source, and the power source of the relay coil 11 is not limited to the commercial power source 5 and may be the power source 22. good. Furthermore, the blower 2 is not limited to an AC motor, but a DC motor is used, and the same effect can be exhibited even if the rotation speed is controlled by controlling the DC voltage.

[0021]

As described in detail above, according to the present invention, the speed adjusting means is based on the temperature detecting means, and when the temperature in the storage chamber is lower than a predetermined high temperature, the rotation speed of the blower is set to the normal low speed operation. Therefore, while maintaining the minimum cold air circulation in the storage chamber, it is possible to prevent excessive cold air agitation in the storage chamber and suppress damage such as discoloration of stored articles (food etc.).

When the temperature in the storage chamber is equal to or higher than a predetermined high temperature, the speed adjusting means operates the blower at a high speed, so that a large amount of cold air that has exchanged heat with the cooler is circulated in the storage chamber. The temperature can be lowered rapidly. Therefore, it becomes possible to quickly lower the temperature of the storage room immediately after the cooling storage is installed or when the cooler is defrosted after defrosting, etc., and it is possible to prevent the occurrence of putrefaction of the stored food in advance. It will be.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram of a speed adjustment device portion of a cooling storage control device according to the present invention.

FIG. 2 is an electric circuit diagram of a temperature control device portion of the control device for the cooling storage according to the present invention.

[Explanation of symbols]

 1 Speed Control Device 2 Blower 3 Waveform Control Circuit 4 Variable Resistor 6 Relay Switch 10 Thermostat 11 Relay Coil 20 Temperature Control Device 21 Thermostat 23 Refrigerant Control Valve C Control Device

Claims (1)

[Claims] 1. A cooling storage cabinet configured to forcibly circulate cool air that has exchanged heat with a cooler into a storage chamber by a blower, and temperature detection means for detecting a temperature in the storage chamber, and speed control for adjusting a rotation speed of the blower. Means is provided, and the speed adjusting means is based on the temperature detecting means, when the temperature in the storage chamber is higher than or equal to a predetermined high temperature, the rotation speed of the blower is set to high speed operation, and when it is lower than that, the blower The cooling storage control device is characterized in that the rotation speed of the engine is set to a normal low speed operation.