JP6662118B2 - Vacuum cooling device - Google Patents

Description

  The present invention relates to a vacuum cooling device for cooling foods, foods, and the like.

  As disclosed in Patent Document 1 and Patent Document 2, etc., the inside of a processing tank containing a cooled object is depressurized to vaporize moisture in the cooled object, and the cooled object is cooled by the heat of vaporization. Vacuum cooling devices are known. In such a vacuum cooling device, an article temperature sensor is attached to an object to be cooled, and vacuum cooling to a target temperature zone is performed based on the temperature of the article to be cooled by the article temperature sensor.

  Patent Document 1 describes that pressure reduction control is performed by detecting the pressure in a processing tank, and pressure reduction control is performed by time control when a pressure sensor fails.

  Patent Literature 2 describes that the temperature of the same object to be cooled is detected by two temperature sensors and the cooling operation is controlled based on the detected temperatures. It is described that when an abnormality occurs in one of the product temperature sensors, the cooling operation is controlled based on the detected temperature of the product temperature sensor in which no abnormality has occurred.

  In Patent Document 3, in order to prevent deterioration of the quality of the object to be cooled due to excessive cooling or the like due to forgetting to insert the item temperature sensor, it is determined whether to forget to insert the item temperature sensor before or after cooling of the object to be cooled is started. It describes that when it is determined that the user has forgotten, the cooling of the object to be cooled is not started or the cooling is stopped.

In the alternative control based on time described in Patent Document 1, a difference occurs between the actual temperature of the object to be cooled and the required degree of pressure reduction. Further, depending on the object to be cooled, poor quality due to the temperature difference or reduction in the yield due to scattering occurs. There is a problem that happens.
The method described in Patent Literature 2 is based on the premise that a plurality of product temperature sensors are provided, and is applied to a cooling device that controls a cooling operation based on the detection temperature of one product temperature sensor. Can not.
The method described in Patent Literature 3 does not start cooling of the object to be cooled or stops cooling when it is determined that the product temperature sensor is forgotten to be inserted, and does not disclose an alternative method of cooling control. Absent.

JP-A-11-137227 JP 2001-208617 A JP 2010-144981 A

  When controlling the cooling operation based on the temperature detected by the product temperature sensor, if there is an abnormality such as failure of the product temperature sensor or improper insertion, there is no other method than stopping the operation of the vacuum cooling device. .

  An object of the present invention is to provide a vacuum cooling device that can continue a cooling operation without stopping a cooling control even when an abnormality such as a failure of a product temperature sensor or a poor insertion occurs.

  The present invention provides a cooling tank for storing a cooled object, a product temperature sensor for detecting a temperature of the cooled object, a pressure sensor for detecting a pressure inside the cooling tank, and a vacuum suction for depressurizing the cooling tank. A line, a vacuum suction unit connected to the vacuum suction line, and a control unit, wherein the control unit controls the operation of the vacuum suction unit based on a temperature detected by the product temperature sensor. A pressure reduction control unit, a second pressure reduction control unit that controls the operation of the vacuum suction unit based on the pressure detected by the pressure sensor, and a product temperature sensor that determines whether an abnormality has occurred in the product temperature sensor When it is determined by the abnormality determination unit and the temperature sensor abnormality determination unit that an abnormality has occurred in the temperature sensor, the operation control of the vacuum suction unit by the first pressure reduction control unit is stopped, and the second Operation of the vacuum suction unit by the pressure reduction control unit A pressure reduction control switching unit which activates the control relates to a vacuum cooling apparatus comprising a.

  It is preferable that the product temperature sensor abnormality determination unit determines whether an abnormality has occurred in the product temperature sensor based on a rate of change in the temperature detected by the product temperature sensor.

  It is preferable that the article temperature sensor abnormality determination unit determines that an abnormality has occurred in the article temperature sensor when the article temperature sensor does not output a detected temperature.

  It is preferable that the article temperature sensor abnormality determination section determines that an abnormality has occurred in the article temperature sensor when the detected temperature of the article temperature sensor indicates a value outside a predetermined range.

  According to the present invention, even if the product temperature sensor should fail, the pressure can be switched to pressure reduction control based on the pressure detected by the pressure sensor as a backup, and the vacuum cooling device can be continuously operated without stopping.

It is a schematic diagram which shows the schematic structure of one Embodiment of the vacuum cooling device 1 of this invention. FIG. 4 is a functional block diagram illustrating a configuration of a control unit 5 as an operation determination unit and a control switching unit according to the embodiment. 4 is a flowchart illustrating an operation of the vacuum cooling device 1 according to the embodiment. 4 is a flowchart illustrating an operation of the vacuum cooling device 1 according to the embodiment.

  Hereinafter, a preferred embodiment of a vacuum cooling device of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a schematic configuration of one embodiment of a vacuum cooling device 1 of the present invention.

  As shown in FIG. 1, the vacuum cooling device 1 includes a cooling tank 2, a decompression unit 3, a decompression unit 4, and a control device 5.

  The cooling tank 2 stores the object to be cooled 23. The cooling tank 2 is provided with an opening / closing door (not shown) for taking in / out the object 23 to be cooled, and by closing the opening / closing door, the cooling tank 2 can be completely sealed. In the present embodiment, foodstuffs are simultaneously stored in the cooling tank 2 as the objects to be cooled 23.

  The cooling tank 2 is provided with a product temperature sensor 21 for detecting the temperature of a food material, which is the object 23 to be cooled, which is accommodated in the cooling tank 2. The product temperature sensor 21 measures the temperature at the location, for example, by being inserted into a food material stored in the cooling tank 2.

  The cooling tank 2 is provided with a pressure sensor 22 for detecting the pressure in the cooling tank 2.

The decompression means 3 includes a vacuum suction unit 31, which is connected to the cooling tank 2 via a vacuum suction line 33.
The vacuum suction unit 31 includes, for example, a water ring vacuum pump.
Preferably, the vacuum suction line 33 is provided with a heat exchanger 32. Further, a steam ejector (not shown) may be provided on the pressure reducing line 33 on the upstream side of the heat exchanger 32.

  The heat exchanger 32 cools and condenses the food vapor in the vacuum suction line 33 and the vapor of the vapor ejector (when a vapor ejector is provided). By cooling and condensing the food vapor and the vapor from the vapor ejector in the vacuum suction line 33 in advance, the temperature of the fluid in the vacuum suction line 33 is reduced and the volume of the discharged fluid is reduced. By doing so, it is possible to reduce the load on the vacuum suction unit 31 and effectively reduce the pressure in the cooling tank 2.

  The steam ejector sucks and discharges the fluid in the cooling tank 2 by ejecting steam. The pressure on the suction side of the vacuum suction unit 31 can be increased by the steam ejector, and the pressure in the cooling tank 2 can be effectively reduced.

The pressure recovery means 4 is means for introducing outside air into the depressurized cooling tank 2 to release the vacuum state and recover the pressure. Specifically, the outside air is taken in through the filter 41 and can be supplied into the cooling tank 2 through the pressure recovery line 42.
In the middle of the pressure recovery line 42, a pressure recovery operation valve 43 for switching the communication between the outside air and the inside of the cooling tank 2 is provided. Therefore, after the pressure in the cooling tank 2 is reduced by the pressure reducing means 3 with the pressure recovery operating valve 43 closed, the pressure reduction by the pressure reducing means 3 is stopped and the pressure recovery operating valve 43 is opened, whereby the cooling tank 2 is opened. The vacuum state inside can be released to return to the atmospheric pressure.

The opening degree of the pressure recovery operation valve 43 can be arbitrarily adjusted like a proportional control valve. Therefore, when the pressure in the cooling tank 2 is reduced by the pressure reducing means 3, the pressure in the cooling tank 2 can be arbitrarily adjusted by adjusting the opening of the return pressure operation valve 43.
More specifically, the pressure in the cooling tank 2 can be easily adjusted by performing the pressure reducing operation by the pressure reducing means 3 while adjusting the opening of the pressure recovery operating valve 43.

  The control unit 5 controls the pressure reducing means 3, the pressure recovery means 4, and the like. In the present embodiment, the product temperature sensor 21, the pressure sensor 22, the vacuum suction unit 31, and the pressure recovery operation valve 43 are connected to the control unit 5, and the control unit 5 can perform various controls.

FIG. 2 is a functional block diagram illustrating a functional configuration of the control unit 5.
As shown in FIG. 2, the control unit 5 controls the cooling operation so that the cooling operation can be continued without stopping the cooling control even when an abnormality such as a failure of the product temperature sensor 21 or an insertion failure occurs. The apparatus includes a first pressure reduction control unit 51, a second pressure reduction control unit 52, a product temperature sensor abnormality determination unit 53, and a pressure reduction control switching unit 54.

The first decompression controller 51 controls the operation of the vacuum suction unit 31 based on the temperature detected by the product temperature sensor 21 until the detected temperature reaches a preset target temperature. Here, the target temperature is a target cooling temperature of the object 23 to be cooled.
The first pressure reduction control unit 51 stores the object to be cooled 23 in the cooling bath 2 and cools the object to be cooled 23 at a predetermined pressure reduction speed set as a standard speed. The degree of temperature decrease over time, that is, the amount of temperature change (temperature gradient) is measured, and while the opening degree of the pressure recovery operating valve 43 is adjusted based on the amount of temperature change (temperature gradient) of the object 23 to be cooled, the pressure is reduced. By performing the decompression operation by the means 3, the decompression speed in the cooling tank 2 is adjusted. That is, when the temperature change amount is large, the first pressure reduction control unit 51 sets the pressure reduction speed in the cooling bath 2 to be slower than the standard pressure reduction speed, and when the temperature change amount is small, the first pressure reduction control unit 51 The pressure reducing means 3 reduces the pressure by the pressure reducing means 3 while adjusting the opening degree of the pressure recovery operating valve 43 based on the temperature change amount (temperature gradient) of the cooled object 23 so as to make the speed faster than the standard pressure reducing rate so as not to cause bumping. By performing the operation, the pressure reduction rate in the cooling bath 2 is adjusted.
The first pressure reduction control unit 51 measures the temperature change (temperature gradient) over a predetermined elapsed time from the start of the measurement of the object 23 to be cooled, and based on the measured temperature change (temperature gradient), determines the cooling load. The amount may be determined, and the pressure reduction rate in the cooling tank 2 may be adjusted based on the cooling load amount.
The first pressure reducing control unit 51 cools the object to be cooled 23 and stops the pressure reduction by the pressure reducing means 3 when the temperature detected by the product temperature sensor 21 reaches the target temperature, and opens the pressure recovery operating valve 43. As a result, the vacuum state in the cooling tank 2 is released to return to the atmospheric pressure.
After the temperature detected by the product temperature sensor 21 reaches the target temperature, the first decompression control unit 51 performs, for example, a decompression operation valve in accordance with the characteristics of the cooled object 23 (for example, cooling characteristics such as difficulty in cooling). By performing the decompression operation by the decompression means 3 while adjusting the opening degree of 43, the decompression by the decompression means 3 is stopped after the temperature detected by the product temperature sensor 21 has maintained the target temperature for a predetermined time (maintenance time). Then, by opening the pressure recovery operation valve 43, the vacuum state in the cooling tank 2 may be released to return to the atmospheric pressure. By doing so, it is possible to eliminate cooling unevenness.

  As described above, the first pressure reducing control unit 51 adjusts the opening degree of the return pressure operation valve 43 based on the temperature change amount measured by the product temperature sensor 21 or the cooling load amount determined from the temperature change amount. Meanwhile, the decompression operation by the decompression means 3 is performed to adjust the decompression speed in the cooling bath 2, and the decompression by the decompression means 3 is stopped when the temperature detected by the product temperature sensor 21 reaches the target temperature.

The second pressure reduction control section 52 controls the operation of the vacuum suction section 31 based on the pressure detected by the pressure sensor 22. Specifically, the second pressure reducing control unit 52 reduces the pressure until the internal pressure of the cooling bath 2 reaches a target pressure value calculated based on a preset target temperature.
Here, the target pressure value may be calculated as a saturation pressure corresponding to the target temperature. Further, depending on the object to be cooled 23, it is not always cooled immediately. Therefore, a saturation pressure value corresponding to the first target temperature obtained by subtracting a predetermined temperature ΔT (for example, 2 degrees) from the target temperature is set as the saturation pressure value. It may be calculated.
The second depressurization control unit 52 stores the object 23 to be cooled in the cooling bath 2 and cools the object 23 in the cooling bath 2 at a predetermined reduced pressure speed as a standard speed. By measuring the amount of pressure change over the elapsed time of, and performing the depressurizing operation by the depressurizing means 3 while adjusting the opening degree of the pressure recovery operating valve 43 based on the amount of pressure change of the cooled object 23, the cooling tank 2 is configured to adjust the decompression rate. That is, the second pressure reduction control unit 52 sets the pressure reduction rate in the cooling tank 2 to be slower than the standard pressure reduction rate when the pressure change amount is large, and reduces the pressure reduction rate in the cooling tank 2 when the pressure change amount is small. Depressurizing operation by the depressurizing means 3 while adjusting the opening of the return pressure operation valve 43 based on the amount of pressure change in the cooling bath 2 so as to make the speed faster than the standard depressurizing speed so as not to cause bumping. Thus, the pressure reduction rate in the cooling bath 2 is adjusted.
The second decompression controller 52 measures a pressure change amount at a predetermined elapsed time from the start of the measurement of the pressure in the cooling tank 2 and determines a cooling load amount based on the measured pressure change amount. You may comprise so that the pressure reduction rate in the cooling tank 2 may be adjusted based on the cooling load amount.
The second decompression controller 52 cools the object 23 to be cooled, and stops the decompression by the decompression means 3 when the detection pressure of the pressure sensor 22 reaches the target pressure, and opens the decompression operation valve 43.
In addition, according to the characteristics of the cooled object 23 (for example, cooling characteristics such as difficulty in cooling), the second decompression control unit 52 sets the return pressure operation valve 43 after the pressure in the cooling tank 2 reaches the target pressure value. The pressure in the cooling bath 2 is maintained at a target pressure value for a predetermined time (maintenance time) by performing a pressure reducing operation by the pressure reducing means 3 while adjusting the opening degree of the pressure, and then the pressure reduction by the pressure reducing means 3 is stopped. Alternatively, the vacuum state in the cooling tank 2 may be released by returning the pressure-reducing operation valve 43 to return to the atmospheric pressure. By doing so, it is possible to eliminate cooling unevenness.

  As described above, the second pressure reduction control unit 52 adjusts the opening degree of the return pressure operation valve 43 based on the pressure change amount measured by the pressure sensor 22 or the cooling load amount determined from the pressure change amount. By performing the decompression operation by the decompression means 3, the decompression speed in the cooling tank 2 can be adjusted.

  The product temperature sensor abnormality determination unit 53 determines whether an abnormality has occurred in the product temperature sensor 21. Typically, when detecting an abnormal signal of the product temperature sensor 21, the product temperature sensor abnormality determination unit 53 determines that the product temperature sensor 21 has an abnormality.

Further, the product temperature sensor abnormality determination unit 53 can be configured to determine whether or not the product temperature sensor 21 is abnormal based on the rate of change of the temperature detected by the product temperature sensor 21.
For example, when it is determined that the change rate of the detected temperature detected during a predetermined detection time (for example, 5 seconds) is smaller than a first determination temperature change rate set in advance, the article temperature sensor abnormality determination unit 53 determines that the object to be cooled is It may be estimated that the product temperature sensor 21 is not inserted correctly into the product 23 or that the product temperature sensor 21 is removed from the object 23 to be cooled, and that the product temperature sensor 21 is determined to be abnormal.
Similarly, when it is determined that the rate of change of the detected temperature detected during the predetermined detection time is greater than the second rate of change of the predetermined temperature, the temperature sensor abnormality determination unit 53 determines whether the temperature of the cooled object 23 is high. It may be estimated that the product temperature sensor 21 has not been correctly inserted or the product temperature sensor 21 has come off from the object 23 to be cooled, and it may be determined that the product temperature sensor 21 is abnormal.

  The product temperature sensor abnormality determination unit 53 may determine that the product temperature sensor is abnormal when the product temperature sensor 21 does not output the detected temperature.

  In addition, when the temperature detected by the product temperature sensor 21 is out of the measurement range and exceeds the temperature at which the product temperature sensor 21 can be determined normally, the product temperature sensor abnormality determination unit 53 generates an abnormality in the product temperature sensor 21. May be determined.

When the product temperature sensor abnormality determination unit 53 determines that the product temperature sensor 21 is abnormal, the pressure reduction control switching unit 54 stops the operation control of the vacuum suction unit 31 by the first pressure reduction control unit 51. Thereafter, the pressure reduction control switching unit 54 performs vacuum suction by the second pressure reduction control unit 52 so as to reduce the pressure until the internal pressure of the cooling bath 2 reaches a target pressure value calculated based on a preset target temperature. The operation control of the unit 31 is started.
Here, the target pressure value calculated based on the preset target temperature may be calculated in advance by the control unit 5 when the target temperature is set. Further, the pressure reduction control switching unit 54 may calculate the target pressure value based on the target temperature. Alternatively, the second pressure reduction control unit 52 may calculate the target pressure value based on the target temperature.
By doing so, the second pressure reducing control unit 52 reduces the pressure until the internal pressure of the cooling tank 2 reaches the target pressure value. ,

Next, an operation of the vacuum cooling device 1 according to the present embodiment will be described with reference to FIGS. FIG. 3 and FIG. 4 are flowcharts illustrating an example of the operation of the vacuum cooling device 1 according to the present embodiment.
Here, a saturation pressure value P0 corresponding to a first target temperature (T0-ΔT) obtained by subtracting a predetermined temperature ΔT from a target temperature T0, which is a target cooling temperature of the object 23, is calculated in advance. Shall be kept.

In step ST1, to accommodate the object to be cooled in the cooling tank 2, after closing the door, on the basis of the target temperature T ₀ which is input in advance, at the saturation pressure value corresponding to the first target temperature (T ₀ -.DELTA.T) calculating a certain target pressure value P _0.

  In step ST2, when the operation switch is turned ON, the first decompression control unit 51 starts the vacuum cooling device 1 and starts decompression (cooling).

In step ST3, the first pressure reduction control unit 51 based on the detected temperature of the material temperature sensor 21, so that the detected temperature reaches the target temperature T _0, performs the decompression control by pressure reducing means 3.

  In step ST4, the product temperature sensor abnormality determination unit 53 determines whether or not the product temperature sensor 21 has an abnormality. If it is determined that an abnormality has occurred in the product temperature sensor 21 (in the case of Yes), the process proceeds to step ST10. If it is determined that no abnormality has occurred in the product temperature sensor 21 (No), the process proceeds to step ST5.

In step ST5, the first pressure reduction control unit 51 determines whether or not the temperature detected by the material temperature sensor 21 reaches the target temperature T _0. When it reaches the target temperature _{T 0} (the case of Yes) proceeds to step ST6. When it has not reached the target temperature _{T 0} (the case of No), the process returns to step ST3.

  In step ST6, the first pressure reduction control section 51 adjusts the opening degree of the pressure recovery operation valve 43 so that the temperature detected by the product temperature sensor 21 maintains the target temperature for a predetermined time (maintenance time), 3 is performed.

  In step ST7, the first pressure reduction control section 51 stops the pressure reduction by the pressure reducing means 3.

  In step ST8, the first pressure reduction control unit 51 opens the pressure recovery operation valve 43, releases the vacuum state in the cooling tank 2, and returns the cooling tank 2 to the atmospheric pressure.

(Process when an abnormality occurs in the product temperature sensor 21)
In step ST10, the pressure reduction control switching unit 54 stops the pressure reduction control by the pressure reduction unit 3 by the first pressure reduction control unit 51.

  In step ST11, the pressure reduction control switching unit 54 activates the second pressure reduction control unit 52.

In step ST12, the second pressure reduction control unit 52 based on the pressure detected by the pressure sensor 22, so that the detected pressure reaches the target pressure P _0, performs the decompression control by pressure reducing means 3.

In step ST13, the second pressure reduction control unit 52 determines whether the detected pressure by the pressure sensor 22 reaches the target pressure value P _0. When it reaches the target pressure _{P 0} (case of Yes) proceeds to step ST14. If it does not reach the target pressure _{P 0} (case of No), the process returns to step ST12.

In step ST14, the second pressure reduction control unit 52, a predetermined time, so as to maintain the pressure in the cooling tank 2 to the target pressure value P _0, while adjusting the degree of opening of the pressure recovery operation valve 43, by the pressure reducing means 3 Perform a decompression operation.

  In step ST15, the second decompression control unit 52 stops the decompression by the decompression means 3.

  In step ST16, the second pressure reduction control unit 52 opens the pressure recovery operation valve 43, releases the vacuum state in the cooling tank 2, and returns to the atmospheric pressure.

Step ST6 or step ST14 may be omitted according to the characteristics of the cooled object 23 (for example, cooling characteristics such as easy cooling). That is, in step ST5, (case of Yes) when it reaches the target temperature _{T 0} may be configured to move to step ST7. Further, in step ST13, (case of Yes) when it reaches the target pressure _{P 0} may be configured to move to step ST15.

As described above, the vacuum cooling device 1 according to the present embodiment includes the first pressure reduction control unit 51 that controls the operation of the vacuum suction unit 31 and the detection pressure of the pressure sensor 22 based on the temperature detected by the product temperature sensor 21. A second decompression control section 52 for controlling the operation of the vacuum suction section 31 based on the above, an article temperature sensor abnormality judging section 53 for judging whether or not the article temperature sensor 21 is abnormal, and an article temperature sensor abnormality judgment When the unit 53 determines that an abnormality has occurred in the product temperature sensor 21, the operation control of the vacuum suction unit 31 by the first pressure reduction control unit 51 is stopped, and the operation of the vacuum suction unit 31 by the second pressure reduction control unit 52. And a pressure-reduction control switching unit 54 for activating the control.
Thus, even if the product temperature sensor 21 should fail, the pressure can be switched to pressure reduction control based on the pressure detected by the pressure sensor 22 as a backup, and the vacuum cooling device 1 can be continuously operated without stopping.

  In addition, the product temperature sensor abnormality determination unit 53 of the vacuum cooling device 1 of the present embodiment determines whether or not the product temperature sensor 21 has an abnormality based on the rate of change of the detected temperature of the product temperature sensor 21.

  The product temperature sensor abnormality determination unit 53 of the vacuum cooling device 1 according to the present embodiment determines that the product temperature sensor 21 has an abnormality when the product temperature sensor 21 does not output the detected temperature.

Further, the product temperature sensor abnormality determination unit 53 of the vacuum cooling device 1 according to the present embodiment determines that the product temperature sensor 21 has an abnormality when the detected temperature of the product temperature sensor 21 indicates a value outside the predetermined range. I do.
Thereby, abnormality of the product temperature sensor 21 can be found at an early stage, and the pressure can be switched to pressure reduction control based on the pressure detected by the pressure sensor 22.

  As described above, the present invention has been described with the embodiments. However, it is a matter of course that the present invention can be variously modified without changing the gist of the present invention.

[Modification]
In the present embodiment, the vacuum suction unit 31 may use a water-sealed vacuum pump as the vacuum pump. The water ring vacuum pump forms a liquid ring inside by supplying sealed water, and performs suction and discharge of air by rotation of the liquid ring.
Further, a steam ejector may be provided instead or in addition to this.

DESCRIPTION OF SYMBOLS 1 Vacuum cooling device 2 Cooling tank 21 Material temperature sensor 22 Pressure sensor 3 Decompression means 31 Vacuum suction part 32 Heat exchanger 33 Vacuum suction line 4 Recompression means 41 Filter 42 Recompression line 43 Recompression valve 5 Control part 51 First Decompression control unit 52 Second decompression control unit 53 Product temperature sensor abnormality determination unit 54 Decompression control switching unit

Claims (4)

A cooling tank for storing an object to be cooled;
An article temperature sensor for detecting the temperature of the object to be cooled;
A pressure sensor for detecting the pressure inside the cooling bath,
A vacuum suction line for depressurizing the cooling bath,
A vacuum suction unit connected to the vacuum suction line,
A control unit;
With
The control unit includes:
A first decompression control unit that controls the operation of the vacuum suction unit until the detected temperature reaches a preset target temperature based on the detection temperature of the product temperature sensor;
The operation of the vacuum suction unit is controlled based on the pressure detected by the pressure sensor until the detected pressure reaches a saturation pressure value corresponding to a first target temperature obtained by subtracting a predetermined temperature from the target temperature. A second decompression controller,
An article temperature sensor abnormality determination unit that determines whether an abnormality has occurred in the article temperature sensor;
When the product temperature sensor abnormality determination unit determines that the product temperature sensor is abnormal, the control of the operation of the vacuum suction unit by the first pressure reduction control unit is stopped, and the operation by the second pressure reduction control unit is stopped. A decompression control switching unit that starts operation control of the vacuum suction unit,
A vacuum cooling device comprising: The product temperature sensor abnormality determination unit,
The vacuum cooling device according to claim 1, wherein it is determined whether or not an abnormality has occurred in the temperature sensor based on a rate of change in the temperature detected by the temperature sensor. The product temperature sensor abnormality determination unit,
3. The vacuum cooling device according to claim 1, wherein when the temperature sensor does not output a detected temperature, it is determined that an abnormality has occurred in the temperature sensor. 4. The product temperature sensor abnormality determination unit,
4. The vacuum cooling device according to claim 1, wherein when the temperature detected by the temperature sensor indicates a value outside a predetermined range, it is determined that an abnormality has occurred in the temperature sensor. 5. .

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