JP2004170060A - Method of controlling vacuum cooling device and vacuum cooling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the use amount of cooling water in the heat exchanger of a vacuum cooling device. <P>SOLUTION: In this method of controlling the vacuum cooling device 1, a pressure reducing means 7 is connected to a cooling tank 4 storing an object to be cooled 3 through the heat exchanger 6, the heat exchanging capability or the cooling load amount of the heat exchanger 6 is determined, and the drain of the cooling water for the heat exchanger 6 is controlled. In the method of controlling the vacuum cooling device 1, also the pressure reducing means 7 is connected to the cooling tank 4 storing the object to be cooled 3 through the heat exchanger 6 and the drain of the cooling water is controlled based on the temperature of the object to be cooled 3, the outlet temperature of the cooling water for the heat exchanger 6 or the outlet temperature of condensed water of the heat exchanger 6. <P>COPYRIGHT: (C)2004,JPO

Description

  The present invention relates to a control method and a vacuum cooling device for a vacuum cooling device that evaporates water in a cooled object under reduced pressure and uses the latent heat of vaporization for cooling.

  As is well known, a vacuum cooling device vacuum-suctions and cools a cooling tank containing an object to be cooled, thereby lowering a saturated steam temperature and evaporating water in the object to be cooled. The object to be cooled is cooled using the latent heat of vaporization. This vacuum cooling device is used, for example, in the food industry in the step of cooling cooked food.

  As the vacuum cooling device, various devices for reducing the pressure (vacuum suction) in the cooling tank have been proposed and put to practical use. For example, there is one in which most of the steam is condensed by a heat exchanger, and further, a vacuum pump is operated to reduce the pressure to suck air and steam. In this case, a large amount of cooling water for condensing steam in the heat exchanger was required (for example, see Patent Document 1).

Patent No. 2932905

  The problem to be solved by the present invention is to reduce the amount of cooling water used in a heat exchanger of a vacuum cooling device.

  SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and the invention according to claim 1 is a vacuum cooling method in which a decompression means 7 is connected to a cooling tank containing an object to be cooled via a heat exchanger. A method for controlling an apparatus, characterized in that a heat exchange capacity or a cooling load of the heat exchanger is determined, and drainage of cooling water for the heat exchanger is controlled.

  The invention according to claim 2 is a method for controlling a vacuum cooling device in which a decompression means is connected to a cooling tank containing an object to be cooled via a heat exchanger, wherein the temperature of the object to be cooled and the heat The drainage of the cooling water is controlled based on the outlet temperature of the cooling water for the exchanger or the outlet temperature of the condensed water of the heat exchanger.

  According to a third aspect of the present invention, in the second aspect, when the temperature difference between the product temperature and any one of the outlet temperatures is smaller than a predetermined temperature difference, control is performed so as to increase the drainage amount of the cooling water. It is characterized by:

  Further, the invention according to claim 4 is characterized in that a decompression means is connected via a heat exchanger to a cooling tank containing the object to be cooled, and an article temperature detecting means for detecting an article temperature of the object to be cooled; An outlet temperature detecting means for detecting an outlet temperature of the cooling water for the exchanger or a condensed water of the heat exchanger, and a drain control means for controlling drainage of the cooling water are provided.

  As described above, according to the present invention, only the high-temperature cooling water is drained, so that the amount of cooling water used in the heat exchanger of the vacuum cooling device can be reduced.

(Embodiment 1)
An embodiment of the present invention will be described. This embodiment is performed in a vacuum cooling process for cooling food or the like (hereinafter, referred to as “cooled object”) using a decompression unit. First, a vacuum cooling device applied to the embodiment of the present invention will be described.

  The vacuum cooling device includes: a cooling tank containing the object to be cooled; a heat exchanger connected to a suction path of the cooling tank; a pressure reducing unit connected downstream of the heat exchanger; A cooling water supply means for the container, an article temperature detecting means for detecting an article temperature of the object to be cooled, an outlet temperature detecting means for detecting an outlet temperature of the cooling water for the heat exchanger, and a drainage of the cooling water. It comprises drain control means for controlling and a controller for controlling the operation of the vacuum cooling device.

  The heat exchanger condenses water vapor in the suction fluid from the cooling tank. The heat exchanger includes a heat exchange means, for example, a coil. Since the saturated vapor temperature of the suction fluid is higher than the cooling water flowing in the coil, the water vapor condenses on the surface of the coil, so that the partial pressure of the water vapor in the suction fluid decreases, and the air The partial pressure increases. That is, the heat exchanger increases the proportion occupied by air in the suction fluid.

  The depressurizing means is, for example, a positive displacement vacuum pump, a liquid ring vacuum pump, an ejector, etc., and the suctioning fluid whose air occupies a main part by the heat exchanger is sucked and exhausted by the depressurizing means. That is, the pressure reducing means is configured to perform a pressure reducing operation.

  The supply means is for supplying cooling water to the heat exchanger, and fills the cooling water into the heat equipment. The supply means is connected to a supply source of room temperature water such as tap water or groundwater. Further, the supply means includes a tank for storing water, a chiller for cooling water in the tank, and a pump and a circulation path for returning the tank to the tank via the coil, that is, for circulating the water.

  The article temperature detecting means detects an article temperature of the object to be cooled. Here, the article temperature is not limited to the temperature directly detected of the article temperature of the object to be cooled, but includes a value obtained by converting a pressure value in the cooling bath into an article temperature.

  That is, the article temperature detecting means is configured so that the article temperature can be directly detected by inserting the temperature detecting section into the object to be cooled, and outputs the detected temperature to the controller. Further, as another form of the article temperature detecting means, instead of directly inserting the temperature detecting section into the object to be cooled to detect the article temperature as described above, the pressure in the cooling tank is detected by a pressure sensor. Preferably, the pressure value is converted into a temperature, and the converted temperature is output to the controller. According to this another aspect, the operation of directly inserting the temperature detection unit into the object to be cooled can be omitted.

  The outlet temperature detecting means is configured to output an outlet temperature of the cooling water for the heat exchanger to the controller.

  The drain control unit drains the cooling water filled with the heat exchanger and having an increased temperature by the supply unit. The drainage control unit is provided downstream of the outlet temperature detection unit, and discharges cooling water to a drainage line by switching a flow path with, for example, a three-way valve, a plurality of solenoid valves, or the like, or It is configured to be able to return to.

  Here, it is also preferable that the drainage control means adjusts the ratio of the flow rate to the tank and the drainage line, instead of switching the flow path of the cooling water.

    The controller determines a heat exchange capacity or a cooling load amount of the heat exchanger based on the product temperature and the outlet temperature, and controls a drainage amount of the cooling water, that is, a flow rate flowing to the drainage line. It has a built-in control unit that outputs a signal for adjusting. The heat exchange capacity of the heat exchanger can be detected by the difference between the product temperature and the outlet temperature, but can be configured to be detected only by the outlet temperature of the heat exchanger. The heat exchange capacity may be referred to as a cooling capacity. The cooling load of the heat exchanger is represented by the calorific value of food, and a change in the cooling load can be detected by detecting the outlet temperature of the condensed water of the heat exchanger. The calorific value of the food can be detected by the product of weight, temperature and specific heat.

  The operation of the vacuum cooling device having such a configuration will be described. First, the object to be cooled is accommodated in the cooling tank, the decompression means is operated, the pressure in the cooling tank is reduced, and the object to be cooled is cooled. At this time, the steam in the suction fluid is condensed by the heat exchanger, and the ratio of the air in the suction fluid is increased, so that the decompression means can efficiently suck the air. Then, when the temperature of the object to be cooled decreases, the pressure inside the cooling tank is restored, and the cooling process ends.

  Next, a control method of the vacuum cooling device will be described. The operation is started by storing the object to be cooled in the cooling tank. Immediately after the start of the operation of the vacuum cooling device, the pressure in the cooling tank is close to the atmospheric pressure, so that it is easy to reduce the pressure, and the heat exchange capacity during the operation of the heat exchanger may be small.

  Therefore, since the temperature of the cooling water may be room temperature, the controller first supplies room temperature water to the heat exchanger but controls so as not to drain. In the state where the normal-temperature water is supplied, the normal-temperature water may be in a state where the flow is stopped, or may be caused to flow by circulation. In this case, the temperature of the cooling water gradually increases due to heat exchange by the heat exchanger. Then, when the cooling process step proceeds and the temperature of the cooling water rises, the heat exchange capacity of the heat exchanger decreases, and when the temperature becomes a temperature at which the required cooling cannot be exhibited, the controller performs the drainage control. By operating the means, high-temperature cooling water is discharged, low-temperature normal-temperature water is supplied to the heat exchanger, and control is performed so as to lower the temperature of the cooling water in the heat exchanger. Thereafter, the controller controls the drainage of the cooling water based on the product temperature and the outlet temperature of the cooling water for the heat exchanger, so that the temperature of the cooling water in the heat exchanger falls within a predetermined temperature range. maintain.

  The drainage control by the controller preferably increases a drainage amount of the cooling water when a temperature difference between the product temperature and the outlet temperature is smaller than a predetermined temperature difference. Further, it is also preferable that the drainage control by the controller is performed such that when the temperature difference is larger than a predetermined temperature difference, control is performed so as to reduce the drainage amount of the cooling water or not to drain the cooling water at all. is there.

  Further, it is effective to add a means for further lowering the temperature of the cooling water in order to increase the degree of pressure reduction, that is, further lower the cooling temperature, in the control of the controller. Specifically, the heat exchange capacity at the time of operation of the heat exchanger is increased. That is, the cooling water supplied to the heat exchanger is switched from room temperature water to cold water in accordance with the operation state of the vacuum cooling device. The temperature of the cold water is reduced by the chiller of the water in the tank, and circulated when necessary.

  As described above, according to this embodiment, only the high-temperature cooling water is drained, so that the amount of cooling water used in the heat exchanger of the vacuum cooling device can be reduced.

  The present invention includes the following second to fourth embodiments.

(Embodiment 2)
Embodiment 2 is a control method of a vacuum cooling device in which a decompression unit is connected to a cooling tank containing an object to be cooled via a heat exchanger, wherein a product temperature of the object to be cooled and the heat exchanger And a control method of a vacuum cooling device for controlling drainage of the cooling water based on the outlet temperature of the condensed water.

(Embodiment 3)
The third embodiment is a vacuum cooling apparatus according to the second embodiment, wherein when the temperature difference between the article temperature and the outlet temperature is smaller than a predetermined temperature difference, the amount of drainage of the cooling water is increased. Is characterized by the following control method.

(Embodiment 4)
In the fourth embodiment, a decompression unit is connected via a heat exchanger to a cooling tank containing an object to be cooled, and an item temperature detecting unit for detecting an item temperature of the object to be cooled, and an outlet of the heat exchanger. A vacuum cooling device comprising an outlet temperature detecting means for detecting a temperature and a drain control means for controlling drain of the cooling water.

  The second to fourth embodiments are the same as the first embodiment based on the outlet temperature of the condensed water of the heat exchanger instead of the outlet temperature of the cooling water of the heat exchanger in the first embodiment. It is used to perform efficient water saving control. Except that an outlet temperature detecting means is provided at the outlet of the heat exchanger, the configuration and operation are the same as those of the first embodiment, and a description thereof will be omitted. Embodiments 2 to 4 can more appropriately detect a decrease in the heat exchange capacity of the heat exchanger or an increase in the cooling load as compared with Embodiment 1. The outlet temperature of the condensed water of the heat exchanger is directly detected, or the temperature of the outlet or outlet pipe of the heat exchanger is detected to detect the condensed water temperature indirectly.

  Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. This embodiment is implemented in a vacuum cooling process for cooling food or the like (hereinafter referred to as “cooled object”) by using a pressure reducing means. First, a vacuum cooling device applied to the embodiment of the present invention will be described. FIG. 1 is a schematic diagram illustrating the vacuum cooling device.

  In FIG. 1, a vacuum cooling device 1 includes a cooling tank 4 for accommodating a large number of objects to be cooled 3, 3 placed on three-stage shelves 2, 2, 2, and a suction path 5 for the cooling tank 4. , A vacuum pump 7 connected downstream of the heat exchanger 6, a cooling water supply unit 8 for the heat exchanger 6, and a product temperature of the object 3 to be cooled. An outlet temperature sensor 12 for detecting a temperature near an outlet 11 of the cooling water passing through the coil 10 in the heat exchanger 6, a drain temperature control means 13 for controlling the drainage of the cooling water, , And a controller 14 for controlling the operation of the vacuum cooling device 1.

  The cooling tub 4 is formed to have a size that accommodates each of the objects to be cooled 3, a door (not shown) for sealing the cooling tub 4, and a decompression to return the pressure in the cooling tub 4 to atmospheric pressure. A line 15, a pressure sensor 16 for detecting the pressure in the cooling bath 4, and the suction path 5 are provided. The pressure recovery line 15 is provided with a filter 17 for purifying air and an air introduction control valve 18.

The heat exchanger 6 condenses water vapor in the suction fluid from the cooling tank 4. Since the saturated steam temperature of the suction fluid is higher than the cooling water flowing in the coil 10, the steam condenses on the surface of the coil 10, so that the partial pressure of the steam in the suction fluid decreases, and The partial pressure of air increases. That is, the heat exchanger 6 increases the proportion occupied by air in the suction fluid. The heat exchanger 6 includes a discharge path 19 that discharges the suction fluid after exchanging heat.

The vacuum pump 7 is connected to the heat exchanger 6 via the discharge path 19. The discharge path 19 is provided with a first check valve 20 that allows a flow in the discharge direction. The vacuum pump 7 is a water-sealed vacuum pump, and includes a water-sealing line 21 for supplying water, and a vacuum pump discharge line 22 for discharging a mixed fluid of the water and the suction fluid.
The water sealing line 21 is provided with a water sealing control valve 23.

  The cooling water supply means 8 includes two systems, a normal temperature water supply line 24 for supplying normal temperature water such as tap water and groundwater, and a cold water line 26 from a chiller 25 for supplying cooling water to the heat exchanger 6. It is composed of supply lines and can be switched individually.

  The room-temperature water supply line 24 is provided with a room-temperature water control valve 27 and a second check valve 28 disposed downstream of the room-temperature water control valve 27 and allowing flow in the water supply direction. On the downstream side of the second check valve 28, the room temperature water supply line 24 is connected to the water sealing control valve 23. The room-temperature water supply line 24 is connected to an inlet (not shown) of the coil 10 on the downstream side of the second check valve 28. The outlet 11 is connected to the first pipe 29.

  Here, the drainage control means 13 will be described. The drain control means 13 includes a first three-way valve 30 and a drain control valve 32 provided in a drain line 31.

  The first pipe 29 is connected to a first inlet 33 of the first three-way valve 30. The first outlet 34 of the first three-way valve 30 is connected to the drain line 31, and the drain line 31 is provided with the drain control valve 32. Further, a second outlet 35 of the first three-way valve 30 is connected to a second pipe 36, and the second pipe 36 has a third port 35 that allows a flow in a direction of flowing out of the second outlet 35. A check valve 37 is provided. The second pipe 36 downstream of the third check valve 37 is connected to a cold water return port 39 of a cold water tank 38 for storing water.

  The chiller 25 is connected to the cold water tank 38 via a pump 41 provided in a third pipe 40 for circulating water in the cold water tank 38. The cold water line 26 is connected to a second inlet 43 of a second three-way valve 42 for switching the flow of the cold water. The third outlet 44 of the second three-way valve 42 joins the second pipe 36 downstream of the third check valve 37 via a fourth pipe 45 and is connected to the cold water return port 39. Have been. Further, a fourth outlet 46 of the second three-way valve 42 joins with the room temperature water supply line 24 on the downstream side of the second check valve 28 via a fifth pipe 47, and an inlet of the coil 10 ( (Not shown).

  The controller 14 includes the vacuum pump 7, the article temperature sensor 9, the outlet temperature sensor 12, the pressure sensor 16, the control valves 18, 23, 27, 32, the chiller 25, and the three-way valves 30, And a control unit (not shown) programmed to control the operation of each of these sensors (excluding the sensors 9, 12, and 16). . The controller 14 controls the operation of the vacuum cooling device 1.

The controller 14 includes the control unit that controls drainage of the cooling water based on the product temperature and the outlet temperature, that is, outputs a signal that adjusts a flow rate of the coolant flowing into the drainage line 31. ing. The control unit also has a function of determining the difference between the two temperatures. Further, the controller 14 includes a conversion means (not shown) for converting a pressure value detected by the pressure sensor 16 used as a backup of the article temperature sensor 9 into a temperature.

  The operation of the vacuum cooling device 1 having such a configuration will be described. First, each object to be cooled 3 is accommodated in the cooling tank 4, and the door is closed and sealed. Next, the vacuum pump 7 is operated to depressurize the inside of the cooling tank 4 to cool each of the objects 3 to be cooled. At this time, the heat exchanger 6 condenses the water vapor in the suction fluid from the cooling tank 4 to increase the ratio of the air in the suction fluid, so that the vacuum pump 7 can efficiently suck the air. To Then, when the temperature of each of the cooled objects 3 decreases, the pressure inside the cooling tank 4 is restored, and the cooling process ends.

  The control method of the vacuum cooling device will be specifically described with reference to FIGS. FIG. 2 is a schematic diagram illustrating the flow of cooling water in a standby step in the operation of the vacuum cooling device 1. FIG. 3 is a schematic diagram illustrating the flow of cooling water in the initial cooling step. FIG. 4 is a schematic explanatory diagram illustrating the flow of cooling water in the middle stage of cooling. FIG. 5 is a schematic explanatory diagram illustrating the flow of cooling water in the latter stage of cooling.

  First, the standby step will be described with reference to FIG. This standby step is a step of pre-cooling the water in the cold water tank 38 for use in the latter cooling step. In FIG. 2, the flow of water is indicated by arrows. First, the controller 14 switches the flow path of the second three-way valve 42 to a state where the second inlet 43 and the third outlet 44 communicate with each other. Then, the pump 41 and the chiller 25 are operated. Then, the water in the cold water tank 38 is supplied to the third pipe 40, the cold water line 26, the fourth pipe 45, the second pipe 36 downstream of the third check valve 37, and the cold water return port 39. And cooled down to a predetermined temperature. The cooling of the water in the chilled water tank 38 by this circulation is continued until the start of the latter cooling step, and a predetermined chilled water temperature is maintained.

  Next, the cooling initial step will be described with reference to FIG. First, each cooling object 3 is accommodated in the cooling tank 4 and the operation is started. Immediately after the operation of the vacuum cooling device 1 is started, since the pressure in the cooling tank 4 is close to the atmospheric pressure, it is easy to reduce the pressure, and the heat exchange capacity when the heat exchanger 6 is operated may be small. . Accordingly, since the temperature of the cooling water may be room temperature, the controller 14 first supplies room temperature water to the heat exchanger 6.

  The supply of the normal temperature water will be described. First, the controller 14 opens the room temperature water control valve 27 with the drainage control valve 32 opened, and connects the flow path of the first three-way valve 30 to the first inlet 33 and the first outlet 34. Is switched to a state in which is communicated with. Then, the room temperature water drains the cooling water that was in the coil 10 and new room temperature water is introduced instead. That is, after a lapse of time during which the coil 10 is filled with fresh room temperature water, the drain control valve 32 is closed, and the room temperature water is not drained.

  In this state, the controller 14 opens the water sealing control valve 23 and operates the vacuum pump 7. Then, the air and water vapor in the cooling tank 4 are sucked by the vacuum pump 7 through the suction path 5, the heat exchanger 6, and the discharge path 19 (indicated by white arrows in FIG. 2). As described above), the water is discharged from the vacuum pump discharge line 22 together with sealing water (in this case, normal temperature water is used), and the pressure in the cooling bath 4 is reduced. The objects to be cooled 3 are cooled by this reduced pressure. On the other hand, the temperature of the cooling water in the coil 10 gradually increases due to the heat exchange in the cooling initial step.

Next, the cooling middle stage process will be described with reference to FIG. When the outlet temperature of the heat exchanger 6 by the outlet temperature sensor 12 exceeds a predetermined value, the controller 14 opens the drainage control valve 32 because the heat exchange capacity of the heat exchanger 6 decreases, The room temperature water having a higher temperature in the coil 10 is drained to the drain line 31, the room temperature water having a lower temperature is supplied to the coil 10, and the temperature of the cooling water in the coil 10 is controlled to be lowered. After the drain valve 32 is opened, when the temperature difference between the product temperature and the outlet temperature of the heat exchanger 6 exceeds a predetermined value, the drain valve 32 is closed again. As described above, the controller 14 controls the drainage of the cooling water by opening and closing the drainage control valve 32 based on the product temperature and the outlet temperature of the cooling water, and controls the cooling water in the coil 10. Is maintained within a predetermined temperature range.

  Next, the latter cooling step will be described with reference to FIG. When the cooling process proceeds and the temperature of the article also decreases, the temperature difference from the normal-temperature water disappears. In order to further lower the cooling temperature of each of the objects to be cooled 3, the temperature of the cooling water is further lowered. That is, the cooling water supplied to the coil 10 is switched from room temperature water to cold water.

  The controller 14 switches the flow path of the cooling water while the operation of the vacuum pump 7 is continued. First, the normal temperature water control valve 27 and the drainage control valve 32 are both closed. Next, the flow path of the first three-way valve 30 is switched to a state where the first inlet 33 and the second outlet 35 communicate with each other. At the same time, the flow path of the second three-way valve 42 is switched to a state where the second inlet 43 and the fourth outlet 46 communicate with each other. Then, the cold water circulates through the third pipe 40, the cold water line 26, the fifth pipe 47, the coil 10, the first pipe 29, the second pipe 36, and the cold water return port 39. In this case, cold water is supplied to the water sealing control valve 23 via the fifth pipe 47. When the cold water is introduced into the coil 10 and the water sealing line 21, the pressure in the cooling tank 4 is further reduced, and the cooling temperature of each of the objects 3 can be lowered. it can.

  The present invention is not limited to the first embodiment. In the first embodiment, the detection of the decrease in the heat exchange capacity of the heat exchanger 6 is detected by the outlet temperature detecting means 12 for detecting the outlet temperature of the cooling water of the heat exchanger 6. However, as shown in FIG. 5, the outlet temperature detecting means 12 for detecting the outlet temperature of the condensed water of the heat exchanger 6 can be configured to detect a decrease in the heat exchange capacity of the heat exchanger 6. .

  The second embodiment differs from the first embodiment only in the mounting position of the outlet temperature detecting means 12 and other configurations and controls are the same as those in the first embodiment. I do. Also, the operation of the second embodiment is the same as that of the first embodiment, so that the process in the middle stage of cooling will be described, and the other description will be omitted.

  The mid-stage cooling step will be described with reference to FIG. When the outlet temperature of the heat exchanger 6 by the outlet temperature sensor 12 exceeds a predetermined value, the controller 14 opens the drainage control valve 32 because the heat exchange capacity of the heat exchanger 6 decreases, The room temperature water having a higher temperature in the coil 10 is drained to the drain line 31, the room temperature water having a lower temperature is supplied to the coil 10, and the temperature of the cooling water in the coil 10 is controlled to be lowered. After the drain valve 32 is opened, when the temperature difference between the product temperature and the outlet temperature of the heat exchanger exceeds a predetermined value, the drain valve 32 is closed again. As described above, the controller 14 controls the drainage of the cooling water by opening and closing the drainage control valve 32 based on the product temperature and the outlet temperature of the cooling water, and controls the cooling water in the coil 10. Is maintained within a predetermined temperature range.

  According to the second embodiment, as compared with the first embodiment, even when the circulation of the cooling water in the heat exchanger 6 is stopped, a decrease in the heat exchange capacity of the heat exchanger 6 is quickly detected. It has the effect of being able to.

  Further, the present invention includes, as a modified example of the first embodiment and the second embodiment, an embodiment in which the pressure value detected by the pressure sensor 16 is converted into a temperature and controlled.

  In the third embodiment, when the article temperature sensor 9 is an object to be cooled that cannot be used, instead of directly inserting the temperature detecting unit into the article to be cooled 3 as described above to detect the article temperature, It is also preferable that the pressure value in the cooling tank 4 is converted into a temperature by the conversion means, and the converted temperature is output to the controller 14. According to this modification, the operation of directly inserting the article temperature sensor 9 into the article to be cooled 3 can be omitted.

FIG. 1 is a schematic explanatory view illustrating a vacuum cooling device according to an embodiment of the present invention. It is a schematic explanatory view explaining a flow of cooling water of a standby process in operation of a vacuum cooling device. It is a schematic explanatory view explaining a flow of cooling water of a cooling initial process. It is a schematic explanatory view explaining a flow of cooling water of a cooling middle stage process. It is a schematic explanatory view explaining the flow of the cooling water of the latter stage of cooling. It is a schematic explanatory view explaining a vacuum cooling device of another example of the present invention.

Explanation of reference numerals

REFERENCE SIGNS LIST 1 vacuum cooling device 3 object to be cooled 4 cooling tank 6 heat exchanger 7 vacuum pump (decompression means)
9 Article temperature sensor (article temperature detecting means)
12. Outlet temperature sensor (outlet temperature detecting means)
13 Drainage control means

Claims (4)

This is a method for controlling the vacuum cooling device 1 in which a decompression means 7 is connected to a cooling tank 4 containing a cooled object 3 via a heat exchanger 6, wherein a heat exchange capacity or a cooling load of the heat exchanger 6 is determined. And controlling the drainage of the cooling water for the heat exchanger (6). A method for controlling a vacuum cooling apparatus 1 in which a decompression means 7 is connected to a cooling tank 4 containing a cooled object 3 via a heat exchanger 6, wherein the temperature of the article 3 to be cooled and the heat exchanger 6 Controlling the drainage of the cooling water on the basis of the outlet temperature of the cooling water for use or the outlet temperature of the condensed water of the heat exchanger 6. 3. The vacuum cooling device according to claim 2, wherein when a temperature difference between the product temperature and any one of the outlet temperatures is smaller than a predetermined temperature difference, control is performed so as to increase a drainage amount of the cooling water. 4. Control method. A decompression means 7 is connected via a heat exchanger 6 to a cooling tank 4 containing the article 3 to be cooled, and an article temperature detecting means 9 for detecting an article temperature of the article 3 to be cooled; Vacuum cooling, comprising: outlet temperature detecting means for detecting an outlet temperature of cooling water or an outlet temperature of condensed water of the heat exchanger; and a drainage control means for controlling drainage of the cooling water. apparatus.

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