JP2000249455A - Food refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a food refrigerator used in a refrigeration temperature region without freezing foods. SOLUTION: A food refrigerator is adapted such that there are provided a compressor 1.3, a condenser 15, a pressure reducer 23, and coolers 7a, 7b, and a refrigerant is circulated to the coolers 7a, 7b with the operation of the compressor 13 to control chamber temperature to a refrigeration temperature region. There are further provided a food temperature sensor 33, and refrigerant temperature sensors 32a, 32b for detecting refrigerant temperature in the food temperature sensor 33 and the coolers 7a, 7b. There is further provided means for raising the temperature in the coolers 7a, 7b substantially to the set temperature when detection temperature of the food temperature sensor 33 reaches set temperature after foods are introduced into the chamber, and when refrigeration temperature detection by the refrigerant temperature sensors 32a, 32b is lower than set temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a food cooler provided with a plurality of cooling circuits.

[0002]

2. Description of the Related Art Generally, a cooling circuit including a cooling unit including a compressor and a condenser, and a cooler for cooling air in a warehouse is provided by a pipe, and is arranged in an air passage of the cooler when the cooling unit is operated. There is known a food cooler that operates a blower for a cooler, circulates cool air that has exchanged heat in the cooler, and cools food in a refrigeration temperature range.

[0003] A high-temperature food of about 70 ° C cooked in a steam convection oven or the like is introduced into the food cooler.
Rapid cooling to about ° C is required.

[0004]

However, in the conventional configuration, there is a problem that the cooling unit has a large capacity in order to have a sufficient cooling capacity for rapidly cooling the high-temperature food in a short time.

[0005] When the capacity of the cooling unit is increased, the cooling operation in the refrigerator is started, and even when the operation of the compressor is stopped when the temperature detected by the food temperature sensor reaches the set temperature,
Overshoot may cause the food temperature to drop extremely and freeze. There is a problem that food cooled in the refrigeration temperature range cannot be frozen.

[0006] Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art and to provide a food cooler which is used in a refrigeration temperature range where the food does not freeze.

[0007]

According to the first aspect of the present invention,
A food cooler comprising a compressor, a condenser, a decompression device and a cooler, in which the compressor is operated to circulate a refrigerant through the cooler to control the temperature in the refrigerator to a refrigeration temperature range, a food temperature sensor, A refrigerant temperature sensor for detecting a refrigerant temperature of the cooler, wherein after the food is put into the refrigerator, the temperature detected by the food temperature sensor reaches a set temperature, and the refrigerant temperature detected by the refrigerant temperature sensor Means for raising the temperature of the cooler to near the set temperature when the temperature is below the set temperature.

According to the present invention, when the detected temperature of the food temperature sensor reaches the set temperature and the refrigerant temperature detected by the refrigerant temperature sensor is equal to or lower than the set temperature after the food is put into the refrigerator, the cooler is turned off. Since the means for raising the temperature to near the set temperature is provided, the food temperature does not extremely drop due to overshoot.

According to a second aspect of the present invention, there is provided a cooling circuit in which a cooling unit including a compressor and a condenser is connected by a pipe to a cooler for cooling air in the refrigerator, and the cooling unit is operated when the cooling unit is in operation. In a food cooler that operates a cooler blower arranged in an air path and circulates cool air that has exchanged heat with the cooler in the refrigerator, and cools food in a refrigeration temperature range,
Provided with a plurality of cooling circuits for one food cooler,
A food temperature sensor for detecting the food temperature, and a refrigerant temperature sensor for detecting a refrigerant temperature of the cooler, and when the food is put into the refrigerator, all of the plurality of cooling units are operated and cooled. After the temperature of the food temperature sensor reaches the set temperature, the operation of some cooling units is stopped, the operation of the remaining cooling units is controlled, and the capacity of the cooling fan is reduced. Control means for reducing the operation, when the food temperature is detected by the food temperature sensor reaches the set temperature after the food is put into the refrigerator, and the refrigerant temperature detected by the refrigerant temperature sensor is equal to or lower than the set temperature. Means for raising the temperature of the cooler to near the set temperature.

[0010] In the present invention, by providing a plurality of cooling circuits, it is possible to control the operation of all of the plurality of cooling units when the food is put into the refrigerator, and after the temperature detected by the food temperature sensor reaches the set temperature, one cycle is set. The operation of the remaining cooling units can be controlled by shutting down the operation of the cooling units. According to this, each cooling unit is downsized, and after the temperature detected by the food temperature sensor reaches the set temperature, it is only necessary to control the operation of the cooling unit having a small capacity, so that the temperature control width can be narrowed. The control accuracy can be improved. Further, when the temperature detected by the food temperature sensor reaches the set temperature and the refrigerant temperature detected by the refrigerant temperature sensor is equal to or lower than the set temperature after the food is put into the refrigerator, the temperature of the cooler is set close to the set temperature. Because of the provision of the means for raising the food temperature, the food temperature does not extremely drop due to overshoot.

According to a third aspect of the present invention, in the first or second aspect, the means for raising the temperature of the cooler to near the set temperature is means for guiding hot gas from the compressor to the cooler. It is characterized by the following.

According to the present invention, the temperature of the cooler can be raised to near the set temperature within a short time by introducing the hot gas to the cooler.

According to a fourth aspect of the present invention, when the hot gas from the compressor is guided to the cooler in any one of the first to third aspects, the operation of the blower for the cooler is stopped. It is assumed that. This prevents an unnecessary increase in the internal temperature.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a blast chiller (hereinafter referred to as a food cooler). The food cooler 1 includes two cooling units 3a and 3b, and the two cooling units 3a and 3b are connected to coolers 7a and 7b via refrigerant pipes 5, respectively. The coolers 7 a and 7 b are integrally formed in parallel with the air path, and are disposed in the air path leading to the inside 9 of the refrigerator.

The coolers 7a, 7b are provided with three cooler blowers 11a, 11b, 11 for circulating the cool air heat exchanged by the coolers 7a, 7b into the refrigerator 9.
c is attached. These three cooler blowers 11
Each of a, 11b, and 11c has a speed control means (not shown).

One cooling unit 3a is provided with a rated compressor 13
It has. The refrigerant discharge pipe 13a of the rated compressor 13
Is connected to a water-cooled condenser 15.
5 is provided with a water pipe 16. 17 is a solenoid valve for water, 18 is a blower for a compressor, and 19 is an oil cooler of the compressor. Refrigerant outlet pipe 15a of water-cooled condenser 15
, A receiver tank 21 and a dry core 22 are sequentially connected, and further, an expansion valve 23 is connected via a refrigerant pipe 5. The above-described cooler 7a is connected to the expansion valve 23, an accumulator 24 is connected to the cooler 7a via the refrigerant pipe 5, and the accumulator 24 is connected to the refrigerant suction pipe 13b of the rated compressor 13. I have. Further, a bypass pipe 25 is connected to the refrigerant discharge pipe 13 a of the rated compressor 13, and the bypass pipe 25 is connected to a refrigerant outlet pipe 23 a of the expansion valve 23 via a hot gas solenoid valve 26.

Since the two cooling units 3a and 3b have the same configuration, the description of the configuration of the other cooling unit 3b will be omitted.

In this embodiment, as described above, two cooling circuits for connecting a cooling unit and a cooler to one food cooling cabinet 1 are provided. The food cooling cabinet 1 is provided with an in-compartment sensor 31 for detecting an in-compartment temperature and a core temperature sensor (food temperature sensor) 33 for detecting a core temperature of food, and each outlet pipe of the coolers 7a and 7b. Are provided with refrigerant temperature sensors 32a and 32b for detecting the refrigerant temperature.

A high-temperature food of about 70 ° C., for example, heated and cooked in a steam convection oven (not shown) or the like is introduced into the inside 9 of the food cooling cabinet 1. A needle-shaped core temperature sensor 33 is inserted into any one of the foods, and the core temperature of the food is detected by the core temperature sensor 33.

Next, this control operation will be described with reference to FIG.

The temperature detected by the core temperature sensor 33 is compared with the set temperature (S1). If the food temperature is high, such as when the food is charged, the rated compressors 13 of all the cooling units 3a and 3b are used.
Is operated (S2), and the blower 11a for the cooler is
11b and 11c are operated at a high capacity of 60 Hz (S
3), the food temperature drops in a short time.

When the detected temperature of the core temperature sensor 33 reaches the set temperature in S1, the detected temperature of the refrigerant temperature sensor 32a of one of the cooling units 3a is compared with a predetermined temperature (-2 ° C.) (S4). ). When the temperature is lower than the predetermined temperature, the hot gas from the rated compressor 13 is injected into the cooler 7a of the operating cooling unit 3a (S5), and the operation of the cooler blowers 11a, 11b, 11c is stopped. (S6). In this case, referring to FIG.
3 is fully closed, and the hot gas solenoid valve 26 is opened. According to this, hot gas from the rated compressor 13 is supplied to the bypass pipe 25.
The temperature of the cooler 7a rises to near the set temperature (a temperature lower by 2 ° C. than the set temperature indicated by the point a in FIG. 3).

This hot gas injection is performed to prevent the food from freezing due to a temperature drop due to the overshoot by the cooler 7a.

It is preferable that a buzzer beep is sounded when the temperature detected by the core temperature sensor 33 reaches the set temperature. This is because the worker's attention is raised.
It is desirable that this buzzer sound be stopped, for example, when a predetermined time has elapsed or when the door of the food cooler 1 is opened.

FIG. 3 shows a schematic operation in the chilled mode.

As described above, when the food temperature is high, such as when the food is charged, the rated compressors 13 of all the cooling units 3a and 3b are operated (S2), and the blowers 11a, 11b and 11c for the coolers are operated. It is operated at a high capacity of 60 Hz (S3). This corresponds to step 100 in FIG. 3, during which the temperature detected by the core temperature sensor 33 drops rapidly. During this time, the detected temperature used for operation control follows the core temperature sensor 33. According to the core temperature sensor 33, when the process proceeds to step 101, the food temperature may overshoot by the cooler 7a, and the food may be frozen.

Therefore, in step 101, the cooler 7a in the operating cooling unit 3a is operated until the temperature detected by the internal temperature sensor 31 becomes lower by 2 ° C. than the set temperature.
Hot gas from the compressor 13 is injected into the nozzle (S5).

Since the temperature of the cooler 7a rises to near the set temperature due to the injection of the hot gas, the overshoot of the food temperature is suppressed, and the temperature inside the refrigerator reversely rises within a short time, so that the freezing of the food is prevented. Is prevented.

In FIG. 2, after S6 is executed, the temperature detected by the refrigerant temperature sensor 32b of the other cooling unit 3b is compared with a predetermined temperature (-2 ° C.) (S2).
7). When the temperature is lower than the predetermined temperature, the hot gas from the rated compressor 13 is injected into the cooler 7b of the cooling unit 3b in operation (S8), and the blower 1 for the cooler is used.
The operation of 1a, 11b, 11c is stopped (S9). The purpose and effect of this hot gas injection are the same as those described above.

In S4, if the detected temperature of the refrigerant temperature sensor 32a of one of the cooling units 3a is higher than a predetermined temperature (-2.degree. C.), since no overshoot has occurred here, the flow proceeds to S10. This time, the temperature detected by the refrigerant temperature sensor 32b of the other cooling unit 3b is compared with a predetermined temperature (−2 ° C.). When the temperature is lower than the predetermined temperature, hot gas from the rated compressor 13 is injected into the cooler 7b of the operating cooling unit 3b (S10).
8), the operation of the cooler blowers 11a, 11b, 11c is stopped (S9).

In short, the above steps are executed for each cooling unit, and the overshoot of the refrigerant temperature is suppressed by this step, and the food temperature reversely rises to near the set temperature within a short time. Is prevented.

After the above steps, the process proceeds to step 102 in FIG. 3, and the on / off control of the rated compressor 13 is executed.

In the control during this time, it is determined whether six hours have elapsed with reference to FIG. 2 (S11). If six hours have not elapsed, one of the cooling units 3a is shut down, and the rated compressor 1 of the remaining cooling unit 3b is turned off.
3 is operated within a range of ± 1 ° C. with respect to the set temperature (S1
2).

In this case, the detected temperature follows the sensor 31 in the refrigerator. Then, three of the cooler blowers 11a, 11b, and 11c are operated in synchronization with the operation of the rated compressor 13 with equal capacity reduced to 30 Hz (S13).

In S11, if 6 hours have elapsed, a 6-hour elapsed timer is set (S14), and the cooling unit 3b in operation is defrosted (S15). In this case, referring to FIG. 1, the expansion valve 23 is fully closed and the hot gas solenoid valve 26 is opened. According to this, the rated compressor 13
From the cooler 7b through the bypass pipe 25
And the cooler 7b is defrosted.

Next, the operation of the cooling unit 3b, which has been operating so far, is stopped, and the operation is executed by switching to the remaining cooling unit 3a (S16). Then, the operation ends when the operation end switch is turned on (S17).

In this embodiment, the operation of the cooling unit is switched every time the defrosting operation is performed, but the present invention is not limited to this. For example, it is possible to store the accumulated operating time of the operating compressor 13 and switch the operation to the stopped compressor 13 when a certain time has elapsed. In addition, the number of times of operation of the compressor 13 during operation is stored, and when the compressor 13 is operated a certain number of times,
It is possible to switch the operation. In any case, it is desirable to give the cooling unit a priority order of operation stop in advance.

When the priority order of the operation stop is given to the cooling unit, the operation time of the compressor can be made uniform without any one of the cooling units continuously operating, and the durability of the compressor can be improved. it can.

As described above, in this embodiment, the internal cooling operation is started, the temperature detected by the core temperature sensor 33 reaches the set temperature, and the refrigerant temperature detected by the refrigerant temperature sensor 32 is set. At a temperature of -2 ° C below the temperature (+ 3 ° C),
A means (hot gas introduction means) for raising the temperature of the coolers 7a and 7b to near the set temperature is provided.
By a and 7b, the food temperature does not overshoot and drop extremely, and freezing of the food in the refrigerator is prevented.

In this embodiment, the hot gas is supplied to the cooler 7
By guiding the coolers 7a and 7b to the temperatures a and 7b, the temperatures of the coolers 7a and 7b can be increased to near the set temperature within a short time. In addition, it is not limited to hot gas introduction,
For example, a cooler 7 is provided by an electric heater (not shown) or the like.
It is possible to raise the temperatures of a and 7b to near the set temperature.

When the hot gas is introduced, the operation of the cooler blowers 11a, 11b and 11c is stopped. This prevents an unnecessary increase in the internal temperature.

In this embodiment, when a plurality of cooling circuits are provided, the plurality of cooling units 3
When the temperature inside the refrigerator reaches the set temperature and the temperature inside the refrigerator is maintained in the control temperature range (chilled mode), the operation of some of the cooling units is stopped. Control to operate the cooling unit (S12)
Becomes possible.

According to this, each of the cooling units 3a and 3b is reduced in size, and when maintaining the temperature in the refrigerator in the control temperature range (chilled mode), only one of the cooling units 3a and 3b having a small capacity is operated. Temperature control width ± 1
The temperature can be narrowed to the range of ° C., and the control accuracy can be improved. Therefore, the refrigeration temperature range is accurately maintained, so that the food is not frozen. Since a compressor controlled by inverter control is not used, the cost does not increase.

Normally, the blowers 11a, 11b, 1
When the number of rotations of 1c increases, the electric motor of the blower is overheated, and the heat of this electric motor is blown into the inside 9 of the refrigerator, so that the temperature inside the refrigerator rises and the cooling efficiency inside the refrigerator decreases.

In this embodiment, when the temperature in the refrigerator is maintained in the control temperature range, the number of rotations of the blowers 11a, 11b, 11c for the coolers 11a, 11b, 11c is 60 Hz to 30%, which is half of that at the time of feeding the food (S3). (S1
3) Overheating of the blower electric motor is reduced, and the cooling efficiency in the refrigerator can be improved.

Since the number of rotations of each of the cooler blowers 11a, 11b and 11c is reduced equally to three units, the air flow in the air path is reduced uniformly, and therefore, the air flow toward the inside of the refrigerator does not become unbalanced. The occurrence of temperature unevenness is prevented.

As another embodiment, for example, three cooler blowers 11a, 11b and 11c can be constituted by rated blowers. In this case, when the temperature in the refrigerator is maintained in the control temperature range (S12), it is desirable that the operation of any of the blowers 11a, 11b, and 11c for the cooler is stopped to reduce the number of operating units as compared to when the food is charged. This also reduces the amount of overheating of the blower electric motor, thereby suppressing an increase in the internal temperature and improving the internal cooling efficiency.

Although the present invention has been described based on one embodiment, it is apparent that the present invention is not limited to this.

[0050]

According to the first aspect of the present invention, after the food is put into the refrigerator, the temperature detected by the food temperature sensor reaches the set temperature, and the refrigerant temperature detected by the refrigerant temperature sensor is equal to or lower than the set temperature. At this time, since the means for raising the temperature of the cooler to near the set temperature is provided, the cooler prevents the food temperature from overshooting and extremely lowering, thereby preventing freezing of the food in the refrigerator.

According to the second aspect of the present invention, by providing a plurality of cooling circuits, it becomes possible to control the operation of all the plurality of cooling units when the food is put into the refrigerator, and the temperature detected by the food temperature sensor is set to the set temperature. , The operation of some of the cooling units is stopped, and the operation of the remaining cooling units can be controlled.

According to this, each cooling unit is miniaturized, and after the temperature detected by the food temperature sensor reaches the set temperature, it is only necessary to control the operation of the small-sized cooling unit, so that the temperature control width is narrowed. Control accuracy can be improved.

According to the third aspect of the present invention, the temperature of the cooler can be raised to near the set temperature within a short time by introducing the hot gas to the cooler.

According to the fourth aspect of the invention, unnecessary temperature rise of the internal temperature is prevented.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of a food cooler according to the present invention.

FIG. 2 is a flowchart of operation control.

FIG. 3 is a time chart illustrating a schematic operation in a chilled mode.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Blast chiller (food cooler) 3a, 3b Cooling unit 5 Refrigerant piping 7a, 7b Cooler 9 Inside refrigerator 11a, 11b, 11c Blower for cooler 13 Rated compressor 15 Water-cooled condenser 23 Expansion valve 25 Bypass pipe 26 Hot gas Solenoid valve 31 Internal sensor 32a, 32b Refrigerant temperature sensor 33 Core temperature sensor (food temperature sensor)

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Katsuhiko Suzuki 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Masakazu Kurihara 2-chome Keihanhondori, Moriguchi-shi, Osaka No. 5 Sanyo Electric Co., Ltd. (72) Takashi Ishida 2-5-5 Keihanhondori, Moriguchi-shi, Osaka F-term in Sanyo Electric Co., Ltd. 3L045 AA01 AA02 AA03 BA04 BA06 CA02 DA02 EA01 HA02 HA09 JA03 JA14 LA05 LA09 LA10 LA17 MA01 MA02 MA04 NA01 NA03 PA01 PA03 PA05

Claims (4)

[Claims] 1. A food cooler comprising a compressor, a condenser, a decompression device and a cooler, wherein the compressor is operated to circulate a refrigerant through the cooler to control the temperature in the refrigerator to a refrigeration temperature range, A food temperature sensor; and a refrigerant temperature sensor that detects a refrigerant temperature of the cooler. After the food is put into the refrigerator, the detected temperature of the food temperature sensor reaches a set temperature, and the refrigerant temperature A food cooler comprising: means for increasing the temperature of the cooler to near the set temperature when the refrigerant temperature detected by the sensor is equal to or lower than the set temperature. 2. A cooling unit including a compressor and a condenser;
A cooling circuit that is connected by a pipe to a cooler that cools the air in the refrigerator, and when the cooling unit is operated, a cooler blower arranged in an air passage of the cooler is operated to exchange cold air with the cooler. Circulating the inside of the refrigerator, and cooling the food in a refrigeration temperature range, wherein a plurality of the cooling circuits are provided for one food refrigerator, a food temperature sensor for detecting the food temperature, and And a refrigerant temperature sensor for detecting a refrigerant temperature.When food is introduced into the refrigerator, all of the plurality of cooling units are operated, and a blower for the cooler is operated with high capacity, and the detected temperature of the food temperature sensor is detected. After reaching the set temperature, the operation of some of the cooling units is stopped, and the operation of the remaining cooling units is controlled, and control means is provided for operating with reduced capacity of the blower for the cooler, After the food is put into the container, when the temperature detected by the food temperature sensor reaches a set temperature and the refrigerant temperature detected by the refrigerant temperature sensor is equal to or lower than the set temperature, the temperature of the cooler is set to the set temperature. A food cooler comprising a means for raising the temperature to near the temperature. 3. The food cooling apparatus according to claim 1, wherein the means for raising the temperature of the cooler to near the set temperature is means for guiding hot gas from the compressor to the cooler. Warehouse. 4. The food cooler according to claim 1, wherein when the hot gas from the compressor is guided to the cooler, the operation of the blower for the cooler is stopped.