JP2022003289A - Ice-making system and control program for the same - Google Patents

Abstract

To make high-quality ice containing a salt content.SOLUTION: An ice-making system 1 includes an ice-making machine 20, a refrigeration machine 30, a saline concentration sensor 52, a suction thermometer 54 and a control device 10. The ice-making machine 20 is a blade type ice-making machine scraping off ice frozen on an inner wall of an ice-making cylinder 21 by using a blade 22. An evaporator 34 of the refrigeration machine 30 is provided in the ice-making cylinder 21. The saline concentration sensor 52 measures a saline concentration of saline water to be supplied to the ice-making machine 20. The suction thermometer 54 functions as a state sensor acquiring a suction temperature as a value indicating an ice-making state of the ice-making machine 20. The control device 10 controls rotating speed of the blade 22 of the ice-making machine 20 on the basis of the saline concentration and the value indicating the ice-making state so that thickness of the ice becomes less than a first value.SELECTED DRAWING: Figure 1

Description

The present invention relates to an ice making system and a control program thereof.

For example, an ice maker for producing flake-shaped or sherbet-shaped ice using salt water such as seawater as a raw material water is known. For example, Patent Document 1 discloses a technique relating to an ice maker in which raw material water is supplied to an inner wall of a cylinder cooled by a refrigerant and the ice formed on the inner wall is scraped off by a rotating blade. In this ice maker, it is disclosed that the optimum flow rate of the raw material water and the flow rate of the refrigerant are determined based on the salt concentration and the temperature of the raw material water. Further, in this ice maker, it is disclosed that the set value of the rotation speed of the blade may be determined according to the salt concentration of the raw material water.

Japanese Unexamined Patent Publication No. 2013-76553

There are various control parameters of the ice maker, and the ice making state changes variously depending on the combination of these parameters. Especially when producing ice containing salt, the appropriate combination of control parameters may change depending on the salt concentration.
An object of the present invention is to produce high-quality ice containing salt even if the salt concentration changes.

According to one aspect of the present invention, the ice making system includes a blade-type ice making machine that scrapes frozen ice on the inner wall of the ice making cylinder with a blade, a freezer provided with an evaporator in the ice making cylinder, and the ice making machine. A salt concentration sensor that measures the salt concentration of the salt water supplied to the ice machine, a state sensor that acquires a value indicating the ice making state by the ice maker, and a value indicating the salt concentration and the ice making state of the ice. A control device for controlling the rotation speed of the blade of the ice maker is provided so that the thickness is less than the first value.

According to the present invention, high-quality ice containing salt can be produced.

FIG. 1 is a block diagram showing an outline of a configuration example of an ice making system according to an embodiment. FIG. 2 is a flowchart showing an outline of a control example of the operation of the ice making system by the control device according to the embodiment.

[System configuration]
One embodiment will be described with reference to the drawings. The present embodiment relates to an ice making system. In particular, it relates to an ice making system capable of producing fine ice containing salt. The ice produced by this ice making system has a uniform salt concentration regardless of the location of the ice. FIG. 1 is a block diagram showing an outline of a configuration example of the ice making system 1 according to the present embodiment.

As shown in FIG. 1, the ice making system 1 includes an ice making machine 20 for producing ice. The ice maker 20 is provided above the ice storage 48. The ice maker 20 is a blade-type flake ice maker. The ice maker 20 has an ice maker 21, a blade 22, and a motor 23.

The ice making cylinder 21 has a cylindrical shape with an open bottom surface. The inner wall of the peripheral wall of the ice making cylinder 21 is cooled by the refrigerator 30 described later. This inner wall is cooled to a temperature of, for example, -25 ° C. Salt water, which is the raw material water supplied from the water pipe 46 described later, is sprayed onto the inner wall. The sprayed salt water freezes in a short time.

The blade 22 is provided inside the ice making cylinder 21 so that the inner wall of the peripheral wall of the ice making cylinder 21 and the blade of the blade 22 face each other. The blade 22 has a rotation axis that coincides with the central axis of the ice making cylinder 21. The distance between the cutting edge of the blade 22 and the inner wall of the ice making cylinder 21 is small. This interval is not limited to this, but is, for example, 0.1 mm or more and 0.5 mm or less. The rotation shaft of the blade 22 is connected to the motor 23. The motor 23 rotates the blade 22 around a rotation axis. The blade 22 rotating around the axis of rotation scrapes the frozen salt-containing ice on the inner wall of the ice making cylinder 21. The scraped ice falls from the opening on the bottom surface of the ice making cylinder 21. The fallen ice falls into the ice storage 48 through a hole provided in the ceiling of the ice storage 48 and is stored.

As described above, the ice making system 1 includes a refrigerator 30 for cooling the ice making cylinder 21. The refrigerator 30 is, for example, a vapor compression refrigerator. The refrigerator 30 includes a compressor 31, a condenser 32, an expansion valve 33, and an evaporator 34. The evaporator 34 is provided in the ice making cylinder 21 of the ice making machine 20. The compressor 31 compresses the gaseous refrigerant. The condenser 32 cools the compressed refrigerant to produce a high pressure liquid refrigerant. The expansion valve 33 lowers the pressure of the refrigerant. The evaporator 34 vaporizes the refrigerant, takes heat from the ice making cylinder 21 with the heat of vaporization, and cools the ice making cylinder 21. The refrigerant is sent to the compressor 31 again.

The ice making system 1 includes a tank 42, a pump 44, and a water pipe 46. The tank 42 stores salt water as raw material water. The salt concentration of the raw material water is not limited to this, but is, for example, 1%. The pump 44 supplies the raw water stored in the tank 42 to the ice making cylinder 21 of the ice making machine 20 via the water pipe 46.

The ice making system 1 includes a control device 10 for controlling the operation of the ice making machine 20, the refrigerator 30, the pump 44, and the like. The control device 10 includes a CPU (Central Processing Unit) 11, a storage 12, a memory 13, and an interface (I / F) 14. The CPU 11 performs various signal processing and the like. Various information such as control programs and parameters used by the CPU 11 are recorded in the storage 12. Further, the operation history of the ice making system 1 may be recorded in the storage 12. The memory 13 includes a ROM (Read Only Memory) for recording a startup program and the like, a RAM (Random Access Memory) that functions as a main storage device of the CPU 11, and the like. The I / F 14 is an interface between the control device 10 and each part of the ice making system 1. Further, the control device 10 may include an input device (not shown) such as a keyboard for the user to input a set value or the like, a display device (not shown) for displaying various values, and the like. The control device 10 may be configured by using an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array) in which a control program is incorporated.

The ice making system 1 acquires various values related to the state of the ice making system 1 for control by the control device 10. The ice making system 1 specifically acquires values related to ice making. Therefore, the ice making system 1 includes a salinity sensor 52, a suction thermometer 54, an internal thermometer 56, and an outside air thermometer 58.

The salinity sensor 52 measures the concentration of salt contained in the salt water as the raw material water supplied to the ice maker 20. The salinity sensor 52 is provided inside the tank 42, for example. The salinity sensor 52 may be provided in the middle of the water pipe 46 instead of in the tank 42. For example, when the prepared salt water is put into the tank 42, the concentration of the salt water in the tank 42 may change. For example, depending on the environment such as the outside air temperature, the amount of solar radiation, and the state of solar radiation at the place where the ice making system 1 is installed, the water content in the tank 42 may evaporate and the salt concentration of the salt water may change. Further, when the environment such as the outside air temperature, the amount of solar radiation, and the state of solar radiation changes, the amount of evaporation of water in the tank 42 may change. Alternatively, the salt concentration of the salt water in the tank 42 may change due to an error in the preparation of the salt water to be added. The salinity sensor 52 can detect such a change in salinity. The salinity sensor 52 transmits information about the measured salinity to the control device 10. The control device 10 acquires information on the salinity of the raw material water from the salinity sensor 52.

The suction thermometer 54 measures the temperature of the refrigerant at the point where it leaves the evaporator 34 of the refrigerator 30. This temperature will be referred to as the suction temperature. The suction temperature changes depending on the output of the refrigerator 30 and the temperature of the ice making cylinder 21 of the ice making machine 20. Therefore, the suction temperature represents the ice making state in the ice making machine 20. For example, if the suction temperature is higher than a predetermined assumed value, the cooling inside the ice making cylinder 21 may be insufficient as compared with the assumption. For example, if the suction temperature is lower than a predetermined assumed value, there is a possibility that the ice making capacity of the ice making machine 20 has a surplus capacity. In this way, the suction thermometer 54 functions as a state sensor that acquires a value indicating the ice making state by the ice making machine 20. The suction thermometer 54 transmits information about the measured suction temperature to the control device 10. The control device 10 acquires information on the suction temperature from the suction thermometer 54. The control device 10 determines the ice making state based on the suction temperature.

The internal thermometer 56 is provided inside the ice storage 48 and measures the temperature inside the ice storage 48. The internal thermometer 56 transmits the measured information regarding the internal temperature to the control device 10. The control device 10 acquires information on the temperature inside the refrigerator from the thermometer 56 inside the refrigerator. The outside air thermometer 58 measures the temperature of the outside air. The outside air thermometer 58 transmits the measured information regarding the outside air temperature to the control device 10. The control device 10 acquires information on the outside air temperature from the outside air thermometer 58.

When a blade-type ice maker 20 for scraping frozen ice on the inner wall of the ice maker 21 with a blade 22 is used as in the ice maker system 1 of the present embodiment, the thickness of the scraped ice should be thin. Since the inner wall of the ice making cylinder 21 has a low temperature of, for example, −25 ° C., the sprayed salt water freezes immediately. Therefore, near the inner wall of the ice making cylinder 21, ice having a salinity of the sprayed raw water and having a uniform salinity can be formed. On the other hand, when the ice becomes thicker, the salt water sprayed through the thick ice between the inner wall and the inner wall freezes at a distance from the inner wall. For this reason, salt water freezes unevenly over a relatively long period of time. That is, first, the water freezes first in a place near the ice formed on the side closer to the inner wall with a low salinity, and then the salt water in a state with a high salinity in a place far from the ice formed earlier. Freezes. Therefore, ice with different salinity is formed depending on the location. Therefore, the ice making system 1 of the present embodiment is configured to scrape off the ice formed on the inner wall of the ice making cylinder 21 in a thin state.

Based on the acquired information, the control device 10 has the rotation speed of the blade 22 of the ice maker 20, the output of the refrigerator 30, the amount of raw water supplied by the pump 44, that is, the amount of raw water supplied to the ice maker 20. And so on. The control device 10 determines various control parameters so that the thickness of ice formed on the inner wall of the ice making cylinder 21 is less than a predetermined value, and controls the operation of each device, for example. For example, the control device 10 determines a target value of the suction temperature based on the salt concentration, and controls the rotation speed of the blade 22 so that the suction temperature becomes the target value. The thickness of the ice is not limited to this, but is adjusted to, for example, 0.1 mm or more and 1.0 mm or less.

[System operation]
FIG. 2 is a flowchart showing an outline of an operation control example of the ice making system 1 by the control device 10. The operation of the ice making system 1 will be described with reference to FIG.

In step S1, the control device 10 acquires information on the salinity of the raw material water from the salinity sensor 52. Further, the control device 10 acquires the outside air temperature information from the outside air thermometer 58 and the inside temperature information from the inside thermometer 56. Further, the control device 10 acquires information on the reference blade rotation speed, which is a preset value. The reference blade rotation speed is a value set for each individual ice maker 20 for adjusting individual differences of the ice maker 20 and the like. The information on the reference blade rotation speed is recorded in advance in the storage 12 of the control device 10, or is recorded in a memory (not shown) of the ice maker 20. The information of the reference blade rotation speed is used for correction of various control parameters and the like.

In step S2, the control device 10 determines the target value of the suction temperature to be monitored, the liquid feed amount of the pump 44, and the compressor 31 based on the acquired values such as the salt concentration, the outside air temperature, the temperature inside the refrigerator, and the reference blade rotation speed. The initial values of the output of the refrigerator 30 and the rotation speed of the blade 22 such as the rotation speed and the opening degree of the expansion valve 33 which is an electronic expansion valve are determined. These control parameters may be determined by referring to the table recorded in the storage 12 based on the acquired values, or may be calculated and determined by using a predetermined function recorded in the storage. , May be determined by other methods. Hereinafter, the determination of the control parameter may be based on the reference of the table, the calculation each time, or any other method. The control device 10 sets the determined liquid feed amount in the pump 44 and controls the operation of the pump 44. The control device 10 sets the determined output to the refrigerator 30 and controls the operation of the refrigerator 30. The control device 10 sets the determined rotation speed in the ice maker 20 and controls the operation of the motor 23.

For example, when the salt concentration of the raw material water is relatively high, the raw material water is relatively difficult to freeze, so that the temperature of the ice making cylinder 21 of the ice making machine 20 needs to be set relatively low. Therefore, the target value of the suction temperature is set relatively low. When the salinity of the raw water is relatively low, the raw water is relatively easy to freeze. At this time, if the temperature of the ice making cylinder 21 is too low, the ice becomes too thick, which is not preferable. There is also a method of quickly scraping off the ice formed even if the temperature of the ice making cylinder 21 is low, but the temperature of the ice making cylinder 21 may be relatively high in consideration of energy saving and the like. Therefore, the target value of the suction temperature is set relatively high. Similarly, when the outside air temperature and the inside temperature are relatively high, the target value of the suction temperature is set relatively low.

In step S3, the control device 10 acquires the suction temperature from the suction thermometer 54.

In step S4, the control device 10 compares the suction temperature acquired in step S3 with the target value of the suction temperature set in step S2, and controls the rotation speed of the blade 22 so that the suction temperature becomes the target value. do.

For example, when the difference between the measured value of the suction temperature and the target value is smaller than a predetermined value, the control device 10 determines that the rotation speed of the blade 22 is appropriate, and does not change the rotation speed of the blade 22. For example, when the measured value of the suction temperature is higher than the target value, it is considered that the temperature of the inner wall of the ice making cylinder 21 is higher than the target temperature and the raw material water is not sufficiently frozen on the inner wall. Therefore, the control device 10 reduces the rotation speed of the blade 22. This ensures a sufficient time for the raw material water to freeze on the inner wall of the ice making cylinder 21 and prevents the ice that has not been sufficiently frozen from being scraped off. For example, when the measured value of the suction temperature is lower than the target value, it is conceivable that the raw water is frozen too much on the inner wall of the ice making cylinder 21 and the ice is thickened. When the ice becomes thick, the concentration of salt contained in the ice may become uneven on the side far from the inner wall. Therefore, the control device 10 increases the rotation speed of the blade 22. As a result, the blade 22 quickly scrapes off the ice formed on the inner wall of the ice making cylinder 21. As a result, ice with a thin thickness and a uniform salinity can be obtained without making the ice too thick. The amount of change in the rotation speed of the blade 22 may be changed gradually by repeated control as a constant value, or may be changed faster by repeated control as a value calculated based on the difference between the measured value and the target value. You may.

In step S5, the control device 10 determines whether or not the control of the rotation speed of the blade 22 in step S4 is within the controllable range. When it is within the controllable range, the process proceeds to step S6.

In step S6, the control device 10 acquires the salinity information of the raw material water from the salinity sensor 52, the outside air temperature information from the outside air thermometer 58, and the inside temperature information from the inside thermometer 56. get.

In step S7, the control device 10 exceeds a predetermined range in any of the acquired salt concentration, the outside air temperature, and the temperature inside the refrigerator, as compared with the values used when making various settings in step S2. Determine if it has changed. When it has not changed, the process returns to step S3. That is, by the processing of steps S3 to S7, the rotation speed control of the blade 22 based on the suction temperature is continued. As for changes in the outside air temperature and the inside temperature, it is possible to appropriately control the quality of ice by changing the rotation speed of the blade 22 in a relatively wide range. Therefore, this predetermined range is relatively wide for the outside air temperature and the inside temperature. wide.

When it is determined in step S7 that the change has occurred, the process returns to step S2. In particular, when the salt concentration changes, the treatment returns to step S2. At this time, in order to keep the state of the frozen ice in a good state, it is necessary to change the state of the ice making machine 20 such as the temperature of the inner wall of the ice making cylinder 21. For example, when the salt concentration increases, it is necessary to lower the temperature of the inner wall of the ice making cylinder 21 in order to obtain high-quality ice similar to the ice before the increase in concentration. Therefore, the control device 10 determines the target value of the suction temperature, the amount of liquid sent by the pump 44, the rotation speed of the compressor 31, and the opening of the expansion valve 33 based on the acquired changed salt concentration, outside air temperature, and chamber temperature. The output of the refrigerator 30 such as the degree and the rotation speed of the blade 22 are redetermined and reset. For example, when the salt concentration rises, the target value of the suction temperature is lowered. Then, the amount of liquid sent by the pump 44, the output of the refrigerator 30, the rotation speed of the blade 22, and the like are adjusted so that this can be realized. It should be noted that not all of these values need to be changed. For example, the target value of the suction temperature may change, and only the rotation speed of the blade 22 may be changed accordingly. Then, by the processing of steps S3 to S7, the rotation speed of the blade 22 is controlled based on the suction temperature described above.

When it is determined in step S5 that the control of the rotation speed of the blade 22 is not within the controllable range, the process proceeds to step S8. For example, when the inner wall of the ice making cylinder 21 cannot be sufficiently cooled even if the rotation speed of the blade 22 is made lower than the limit value, the rotation speed of the blade 22 cannot be made lower than that, so the process proceeds to step S8. For example, if the rotation speed of the blade 22 is less than 10 rpm, the process proceeds to step S8. Alternatively, if the inner wall of the ice making cylinder 21 is too cold even if the rotation speed of the blade 22 is made higher than the limit value, the process proceeds to step S8.

In step S8, the control device 10 determines whether or not the output of the refrigerator 30 can be changed. When it is determined that the refrigerator 30 output can be changed, the process proceeds to step S9. In step S9, the control device 10 changes the output of the refrigerator 30. For example, when the inner wall of the ice making cylinder 21 cannot be sufficiently cooled, the output of the refrigerator 30 is increased and the ice making cylinder 21 is further cooled. On the other hand, when the inner wall of the ice making cylinder 21 is too cooled, the output of the refrigerator 30 is reduced. After that, the process proceeds to step S6. That is, the rotation speed of the blade 22 is controlled again based on the suction temperature.

When it is determined in step S8 that the output of the refrigerator 30 cannot be changed, the process proceeds to step S10. In step S10, the control device 10 changes the liquid feed amount of the pump 44. For example, when the temperature of the ice making cylinder 21 is still too high even when the output of the refrigerator 30 is maximized, the control device 10 reduces the amount of raw water supplied by the pump 44. Alternatively, when the temperature of the ice making cylinder 21 is still too low even if the output of the refrigerator 30 is minimized, the control device 10 increases the supply amount of the raw water by the pump 44. After that, the process proceeds to step S9. That is, the control device 10 adjusts the output of the refrigerator 30 and controls the rotation speed of the blade 22 according to the suction temperature.

According to the ice making system 1 according to the present embodiment as described above, even if the outside air temperature or the like changes slightly, the rotation speed of the blade 22 is changed to produce ice of a certain thickness in an optimum state. To. In addition, even if the salt concentration of the raw material water changes, the operation of each device is reset, and ice in the optimum state is continuously produced. As described above, in the present embodiment, in particular, control is performed according to the salt concentration of the raw material water, the rotation speed of the blade 22 is controlled, the thickness of the frozen ice is maintained below a predetermined value, and the salt content is maintained. Good quality ice with uniform concentration is produced.

For example, when the salt concentration of the raw material water changes and it is determined in step S7 that the change exceeds a predetermined range and the output of the refrigerator 30 is reset in step S2, or in step. When the output of the refrigerator 30 is changed in S9, the temperature of the inner wall of the ice making cylinder 21 does not change immediately even if the output of the refrigerator 30 is changed. In the present embodiment, the ice making state is appropriate by controlling the rotation speed of the blade 22 in step S4 until the output of the refrigerator 30 is changed and the temperature of the inner wall of the ice making cylinder 21 reaches the target value. Is adjusted to.

For example, when the salt concentration rises, the target temperature of the inner wall of the ice making cylinder 21 is set low, but the actual temperature of the inner wall does not drop immediately and becomes higher than the target temperature. At this time, the rotation speed of the blade 22 is suppressed, and the raw water is adjusted so as to be scraped off by the blade 22 after the raw water is sufficiently frozen. That is, at this time, the rotation speed of the blade 22 is initially lower than the rotation speed assumed as a combination of the salt concentration and the output of the refrigerator 30. As the temperature of the inner wall of the ice making cylinder 21 drops to the target temperature, the rotation speed of the blade 22 is increased, and when the temperature of the inner wall reaches the target temperature, the salt concentration and the output of the refrigerator 30 are displayed. The rotation speed of the blade 22 assumed as a combination of the above is reached.

It is assumed that the output of the refrigerator 30 and the rotation speed of the blade 22 are determined as fixed values for a certain salt concentration by referring to a table or the like. In this case, from the time when the output of the refrigerator 30 is changed until the temperature of the inner wall of the ice making cylinder 21 reaches the target temperature, the ice is scraped off by the blade 22 before the inner wall is sufficiently frozen. Therefore, good ice cannot be obtained. On the other hand, according to the present embodiment, by adjusting the rotation speed of the blade 22, good ice can always be obtained even if the salt concentration or the like changes.

Although the present invention has been described above with reference to preferred embodiments, it is needless to say that the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. Nor.

For example, some of the above parameters may not be used, or other parameters may be used. For example, the liquid feed amount by the pump 44 does not have to be changed. In this case, the temperature of the ice making cylinder 21 of the ice making machine 20 is adjusted by the rotation speed of the blade 22 and the output of the refrigerator 30. Further, the outside air temperature or the inside temperature may not be measured, and these values may not be used for control. Alternatively, the temperature of the raw material water in the water pipe 46 may be measured and controlled using this temperature.

Further, another value may be used instead of the suction temperature as a value indicating the ice making state by the ice making machine 20. For example, a thermometer capable of measuring the temperature of the inside or the inner wall of the ice making cylinder 21 may be provided, and the temperature of the inside or the inner wall of the ice making cylinder 21 may be used as a value indicating the ice making state. Alternatively, a sensor for measuring the thickness of ice on the inner wall of the ice making cylinder 21 may be provided, and the thickness of the ice may be used as a value indicating the ice making state.

1 Ice making system 10 Control device 11 CPU
12 Storage 13 Memory 14 I / F
20 Ice maker 21 Ice maker cylinder 22 Blade 23 Motor 30 Refrigerator 31 Compressor 32 Condensator 33 Expansion valve 34 Evaporator 42 Tank 44 Pump 46 Water supply pipe 48 Ice storage 52 Salt concentration sensor 54 Suction thermometer 56 Inside thermometer 58 Outside air thermometer

Claims (7)

A blade-type ice maker that scrapes frozen ice on the inner wall of the ice-making cylinder with a blade,
A refrigerator equipped with an evaporator in the ice making cylinder, and
A salinity sensor that measures the salinity of the salt water supplied to the ice maker,
A state sensor that acquires a value indicating the ice making state of the ice machine, and
An ice making system including a control device for controlling the rotation speed of the blade of the ice making machine so that the thickness of the ice is less than the first value based on the salt concentration and the value representing the ice making state. .. The state sensor includes a suction thermometer that measures the suction temperature, which is the temperature of the refrigerant at the exit of the evaporator, as a value representing the ice making state.
The control device determines the ice making state based on the suction temperature and controls the rotation speed.
The ice making system according to claim 1. The control device is
Based on the salt concentration, the target value of the suction temperature is determined.
The rotation speed is controlled so that the suction temperature becomes the target value.
The ice making system according to claim 2. The ice making system according to any one of claims 1 to 3, wherein the control device controls the output of the refrigerator based on the salt concentration or a value representing the ice making state. The ice machine is further equipped with a pump for supplying the salt water.
The control device controls the pump to adjust the supply of the salt water to the ice maker based on the salt concentration or a value representing the ice making state.
The ice making system according to any one of claims 1 to 4. The ice making system according to any one of claims 1 to 5, wherein the first value is 0.1 mm or more and 1.0 mm or less. Obtaining the salinity concentration of the salt water supplied to the blade-type ice maker, which scrapes the frozen ice on the inner wall of the ice-making cylinder with a blade, from the salinity sensor,
Obtaining a value indicating the ice making state by the ice maker from the state sensor and
A control program for an ice making system for causing a control device to control the rotation speed of the blade of the ice making machine based on the salt concentration and a value representing the ice making state.

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