JP6946147B2 - Ice machine - Google Patents

Description

The present invention relates to an ice maker that employs an electronic expansion valve whose opening degree is controlled by a control device as an expansion valve of a refrigerating device that cools an ice making section.

Patent Document 1 discloses an ice maker that produces ice in an ice making section. The ice machine of Patent Document 1 has an ice-making unit that freezes ice-making water to produce ice, an ice-making water tank that stores ice-making water that is circulated and supplied between the ice-making units, and an ice-making unit that produces ice-making water in the ice-making water tank. It is equipped with a water supply pump that sends the ice to the ice, a refrigeration device that cools the ice making section, and a control device that controls the operation of the refrigeration device and the water supply pump. The refrigerating device of this ice maker includes a compressor that compresses the refrigerant, a condenser that cools and liquefies the refrigerant pumped from the compressor, an expansion valve that expands the liquefied refrigerant liquefied by the condenser, and expansion. It has an evaporator that vaporizes the liquefied refrigerant expanded by the valve and cools the ice making part, and the liquefied refrigerant that is pumped from the compressor and liquefied by the condenser is expanded by the expansion valve and expanded. The ice making section is cooled by the heat of vaporization of the refrigerant vaporized by the evaporator. When the ice making operation is performed by this ice making machine, the ice making water in the ice making water tank is jetted and sent to the ice making section cooled by the refrigerating device by the water supply pump, and the sent ice making water circulates between the ice making water tank and the ice making section. While being cooled, the ice-making water freezes in the ice-making part and becomes ice.

In this ice maker, when the temperature of the ice making water in the ice making water tank drops to the set temperature near 0 ° C after the ice making operation is started, the water supply pump is stopped for the set time and the water supply pipe is stopped during the set time. The ice making water is controlled to be supplied to the ice making water tank from the ice making water, and the temperature of the ice making water is controlled to be maintained higher than 0 ° C. I try to prevent the inside from becoming cloudy.

Japanese Unexamined Patent Publication No. 2008-2281262

In the ice machine of Patent Document 1 described above, when the temperature of the ice making water in the ice making water tank drops to a set temperature near 0 ° C. after the ice making operation is started, the water supply pump is stopped for a set time and set. Controlled to supply ice making water from the water supply pipe to the ice making water tank over time, controlled to keep the ice making water temperature above 0 ° C, and overcooled when the ice making water begins to freeze I try to prevent it from becoming cloudy. However, if the water pump is temporarily stopped during the ice making operation and the ice making water is controlled to be further supplied to the ice making water tank, there is a problem that the time required for the ice making operation becomes long. An object of the present invention is to prevent the ice from becoming cloudy due to supercooling without lengthening the time required for the ice making operation.

In order to solve the above problems, the present invention uses an ice making section that freezes ice making water to produce ice, an ice making water tank that stores ice making water that is circulated and supplied between the ice making sections, and ice making water in the ice making water tank. A water pump that sends out to the ice making section, a compressor that compresses the refrigerant, a condenser that cools and liquefies the refrigerant pumped from the compressor, and an electronic expansion valve that expands the liquefied refrigerant liquefied by the condenser. A refrigerating device having an evaporator that vaporizes the liquefied refrigerant expanded by the electronic expansion valve to cool the ice making section, and a control device for controlling the operation of the water supply pump and the refrigerating device are provided, and the ice is made in the ice making section. In the ice-making operation to be manufactured, the liquefied refrigerant pumped from the compressor and liquefied by the condenser is expanded by the electronic expansion valve whose opening degree is controlled by the control device, and the expanded liquefied refrigerant is vaporized by the evaporator. The ice making part is cooled by the heat of vaporization, the ice making water sent by the water supply pump is cooled by the cooled ice making part, the unfrozen ice making water is collected in the ice making water tank, and the ice making water is gradually frozen in the ice making part. It is an ice maker that manufactures ice by making it provide a temperature sensor that detects the temperature of the ice making water, and the control device electronically expands when the detection temperature detected by the temperature sensor reaches a predetermined temperature before the start of freezing of the ice making water. Provided is an ice maker characterized in that the opening degree of a valve is controlled to be repeatedly increased and decreased.

The ice maker configured as described above is provided with a temperature sensor that detects the temperature of the ice making water, and the control device has an electronic expansion valve when the detection temperature detected by the temperature sensor reaches a predetermined temperature before the start of freezing of the ice making water. Since it was controlled to repeat increasing and decreasing the opening degree, the state of the liquefied refrigerant sent to the evaporator of the ice making part can be changed to change the cooling state of the ice making part, and the water supply pump. It was possible to prevent the ice-making water frozen in the ice-making part from becoming overcooled and prevent the ice from becoming cloudy without stopping the ice-making operation and prolonging the time required for the ice-making operation.

In the ice maker configured as described above, when the detection temperature detected by the temperature sensor reaches the predetermined temperature before the start of freezing of the ice making water, the electronic expansion valve is opened at the maximum opening and the minimum opening or closed. It may be controlled to repeat. Further, in the ice machine configured as described above, when the detection temperature detected by the temperature sensor reaches a predetermined temperature before the start of freezing of the ice making water, the electronic expansion valve so as to make the gradient of the temperature decrease of the ice making part gentle. It may be controlled to repeat increasing and decreasing the opening degree of. Further, in the ice maker configured as described above, it is preferable to set the temperature to 3 ° C. to 4 ° C. as a predetermined temperature before the start of freezing of the ice making water.

It is the schematic of the ice making machine by this invention. It is a block diagram of a control device.

Hereinafter, an embodiment of the ice machine of the present invention will be described with reference to the drawings. As shown in FIG. 1, the ice machine 10 closes a large number of downwardly open ice making chambers 13 provided in the ice making portion 11 by a water tray 22 so as to be openable and closable, and ice is made from the water tray 22 to each ice making chamber 13. It is a so-called closed cell type ice maker that injects and sends water to produce ice. The ice making machine 10 alternately executes an ice making operation in which the ice making water is frozen in the ice making unit 11 and an ice removing operation in which the ice frozen in the ice making unit 11 is removed from the ice making unit 11 to produce ice. The expansion valve of the refrigerating device 30 that cools and heats the ice making section 11 employs an electronic expansion valve 33 whose opening degree can be adjusted by the control of the control device 40.

The ice making section 11 has a shallow box shape with an open lower surface arranged horizontally, and a large number of ice making chambers 13 are formed by the partition members 12. Further, below the ice making section 11, an ice storage 14 for storing ice produced in each ice making chamber 13 is provided.

The ice machine 10 includes a water supply unit 20 that sends ice-making water to the ice-making unit 11. The water supply unit 20 includes a water dish 22 integrally provided with an ice making water tank 21 at the bottom. The ice-making water tank 21 stores ice-making water that is circulated and supplied to the ice-making unit 11. The water dish 22 is tiltably supported between a closed position where the ice making chamber 13 is closed by approaching the lower side of the ice making portion 11 and an open position where the ice making chamber 13 is opened away from the lower side of the ice making portion 11. Has been done. The water dish 22 is provided with an opening / closing mechanism 23 that tilts between the closed position and the open position, and the water dish 22 opens / closes the ice making chamber 13 of the ice making section 11 by the opening / closing mechanism 23. The opening / closing mechanism 23 includes an actuator motor 23a, and the water pan 22 is tilted between the closed position and the open position by driving the actuator motor 23a.

The water supply unit 20 is provided with a water supply means 24 for supplying ice-making water to the ice-making water tank 21, and a water-feeding pump 25 for injecting and sending out the ice-making water in the ice-making water tank 21 to the ice-making chamber 13. The water supply means 24 includes a water supply pipe 24a connected to the ice making water tank 21 and a water supply valve 24b interposed in the water supply pipe 24a, and the ice making water sent from the water supply pipe 24a is an ice making water tank by opening the water supply valve 24b. It is supplied to 21. The ice-making water supplied to the ice-making water tank 21 is jetted and sent out to the ice-making chamber 13 by the water supply pump 25.

The ice machine 10 includes a refrigerating device 30 that cools and heats the ice making unit 11. The refrigerating device 30 expands a compressor 31 that compresses the refrigerant, a condenser 32 that cools and liquefies the refrigerant pumped from the compressor 31, and a liquefied refrigerant liquefied by the condenser 32 to liquefy the low pressure. It includes an electronic expansion valve 33 as a refrigerant and an evaporator 34 that vaporizes the liquefied refrigerant expanded by the electronic expansion valve 33 to cool the ice making section 11. In the freezing device 30, the compressor 31, the condenser 32, the electronic expansion valve 33, and the evaporator 34 are connected in an annular shape by a refrigerant pipe to form a freezing circuit. The electronic expansion valve 33 is an expansion valve (electric expansion valve) whose opening degree can be adjusted by a control signal of a control device 40 described later. The evaporator 34 is spirally arranged on the upper surface of the ice making section 11, and the ice making section 11 is cooled by the heat of vaporization when the liquefied refrigerant passing through the evaporator 34 is vaporized.

Further, the freezing device 30 includes a hot gas pipe (hot gas path) 35 that supplies hot gas to the evaporator 34 during the deicing operation. The hot gas pipe 35 connects the downstream of the compressor 31 and the upstream of the evaporator 34 so that the hot gas from the compressor 31 is guided to the evaporator 34. A hot gas valve 36 is interposed in the hot gas pipe 35, and the hot gas sent from the compressor 31 is guided to the evaporator 34 through the hot gas pipe 35 by opening the hot gas valve 36. When the hot gas is guided to the evaporator 34 by opening the hot gas valve 36 during the deicing operation, the inside of the ice making chamber 13 of the ice making section 11 is heated by the hot gas, and the frozen ice in the ice making chamber 13 is deiced. Will be done.

The ice making section 11 is provided with a temperature sensor 37, and the temperature sensor 37 detects the temperature of the ice making section 11. Further, the temperature sensor 37 detects the temperature of the ice-making water through the temperature of the ice-making unit 11. The temperature sensor 37 is mainly used for controlling the opening degree of the electronic expansion valve 33 during the ice making operation, as well as the completion of ice making during the ice making operation and the completion of deicing during the deicing operation. Is used to detect. In this embodiment, the temperature sensor 37 is provided at the center of the ice making section 11, but the present invention is not limited to this, and the temperature sensor 37 is provided at the inlet of the refrigerant of the evaporator 34 of the ice making section 11 and the temperature sensor 37. / Or it may be provided at the outlet portion, or a temperature sensor 37 may be provided in the ice making water tank 21 to directly detect the temperature of the ice making water and indirectly from the temperature of the ice making water of the ice making portion 11. It may be designed to detect the temperature.

The ice maker 10 includes a control device 40, and as shown in FIG. 2, the control device 40 includes an actuator motor 23a of the opening / closing mechanism 23, a water supply valve 24b, a water pump 25, and a compressor 31 of the refrigerating device 30. , Is connected to the hot gas valve 36 and the temperature sensor 37. The control device 40 has a microcomputer (not shown), and the microcomputer includes a CPU, RAM, ROM, and a timer (all of which are not shown) connected via a bus. The control device 40 performs an ice making program that repeatedly executes an ice making operation in which the ice making water is frozen in the ice making unit 11 to produce ice and an ice removing operation in which the ice frozen in the ice making unit 11 is removed by the ice making operation. Have.

Next, the ice making program of the ice making machine 10 will be described. When the ice maker 10 is started, a preliminary ice removal operation is performed so that no ice remains in the ice making chamber 13 of the ice making section 11. In the deicing operation, the hot gas valve 36 is opened while the compressor 31 is operated, and the water pan 22 is tilted to the open position by the actuator motor 23a of the opening / closing mechanism 23. The hot gas sent from the compressor 31 is guided to the evaporator 34 through the hot gas pipe 35 to heat each ice making chamber 13 of the ice making section 11. When the detection temperature of the temperature sensor 37 becomes 5 ° C. or higher as a predetermined temperature for detecting that the deicing is completed, the control device 40 has no ice left in the ice making chamber 13 of the ice making section 11, that is, the deicing is completed. The hot gas valve 36 is closed when the hot gas valve 36 is detected. When the hot gas valve 36 is closed, the refrigerant pumped from the compressor 31 does not pass through the hot gas pipe 35 and is sent to the condenser 32, and the liquefied refrigerant liquefied by the condenser 32 undergoes electronic expansion. The valve 33 expands to become a low-pressure liquefied refrigerant, and the low-pressure liquefied refrigerant is vaporized by the evaporator 34 to cool the ice making section 11. Further, the control device 40 supplies ice-making water to the ice-making water tank 21 by tilting the water dish 22 to the closed position by the actuator motor 23a of the opening / closing mechanism 23 and opening the water supply valve 24b. When the ice making water tank 21 reaches a predetermined water level, the control device 40 closes the water supply valve 24b to end the water supply.

After the ice making unit 11 executes the ice removing operation in advance, the control device 40 repeatedly executes the ice making operation and the ice removing operation in the ice making unit 11. As described above, when the hot gas valve 36 is closed, the refrigerant pumped from the compressor 31 is liquefied by the condenser 32 to become a liquefied refrigerant, and the liquefied refrigerant is expanded by the electronic expansion valve 33 to become a low-pressure liquefied refrigerant. It is sent to the evaporator 34 of the ice making section 11. At this time, since it is not necessary to cool the ice-making water until the water-feeding pump 25 starts sending the ice-making water to the ice-making unit 11, the load required to cool the ice-making unit 11 is small, and the control device 40 electronically expands. The opening degree of the valve 33 is smaller than the middle between the maximum and the minimum, and specifically, the opening degree is equivalent to the opening degree of the electronic expansion valve 33 which is controlled when the temperature of the ice making unit 11 becomes 0 ° C. or less. It is controlled to be. In this way, when the load required to cool the ice making section 11 is small, the opening degree of the electronic expansion valve 33 is narrowed to make it smaller so that the ice making section 11 is quickly cooled by the refrigerant having a low temperature. ..

In the ice making operation, with the ice making section 11 sufficiently cooled as described above, the ice making water in the ice making water tank 21 is started to be sent to each ice making small chamber 13 of the ice making section 11 by the water pump 25. Since the temperature of the ice-making water in the ice-making water tank 21 is not low because it is before circulating between the ice-making part 11 and the ice-making part 11, the load for cooling the ice-making water in the ice-making part 11 is high. When the ice making water is started to be sent to the ice making section 11, the refrigerant is sent to the ice making section 11 at the same opening degree as the opening degree of the electronic expansion valve 33 which is controlled when the temperature of the ice making section 11 becomes 0 ° C. or lower. , There is a possibility that the refrigerant required for cooling cannot be delivered to the entire ice making section 11. Further, even though it is necessary to send a large amount of refrigerant to the ice making section 11, if the opening degree of the electronic expansion valve 33 is controlled based on the temperature detected by the temperature sensor 37, the opening degree of the electronic expansion valve 33 can be responsively improved. It may be out of control. Therefore, the control device 40 of the ice making machine 10 determines the opening degree of the electronic expansion valve 33 when the ice making water in the ice making water tank 21 is started to be sent to each ice making chamber 13 of the ice making section 11 by the water supply pump 25. The opening degree of the ice making unit 11 is controlled to be larger than the opening degree of the electronic expansion valve 33 which is controlled when the temperature of the ice making unit 11 becomes 0 ° C. or lower. As a result, when the ice-making water in the ice-making water tank 21 is started to be sent to each ice-making chamber 13 of the ice-making section 11 by the water pump 25, the opening degree of the electronic expansion valve 33 is sufficiently opened without being based on the detection temperature of the temperature sensor 37. It has become possible to deliver a large amount of refrigerant with good responsiveness to the ice making unit 11 by controlling the opening degree at which a large amount of refrigerant can be delivered.

Further, as described above, the electronic expansion valve 33 has a predetermined opening degree from the start of sending the ice-making water in the ice-making water tank 21 to the ice-making unit 11 by the water supply pump 25 until the rise of the detection temperature of the temperature sensor 37 stops. Under the above control, the ice-making water in the ice-making water tank 21 is cooled by sending a large amount of refrigerant with good responsiveness to the ice-making unit 11 until the ice-making water in the ice-making water tank 21 is sufficiently cooled. I try to shorten the time that is done. Further, the ice-making water in the ice-making water tank 21 circulates with the ice-making unit 11 and is gradually cooled. In order to freeze the ice-making water in the ice-making chamber 13 of the ice-making unit 11, the evaporator 34 of the ice-making unit 11 is used. It is necessary to raise the degree of superheat by suppressing the flow rate of the transmitted refrigerant to lower the temperature of the ice making section 11. Therefore, when the ice-making water in the ice-making water tank 21 is cooled to some extent and the detection temperature of the temperature sensor 37 starts to decrease, the opening degree of the electronic expansion valve 33 is controlled to be reduced. After that, the control device 40 controls the opening degree of the electronic expansion valve 33 to be gradually reduced based on the temperature detected by the temperature sensor 37, and freezes the ice making water in the ice making chamber 13 of the ice making section 11. Let me.

Further, when the detection temperature of the ice making unit 11 detected by the temperature sensor 37 becomes 4 ° C. or less as a predetermined temperature before the start of freezing of the ice making water, the control device 40 increases or decreases the opening degree of the electronic expansion valve 33. It is controlled to repeat. Specifically, the control device 40 controls the electronic expansion valve 33 to be repeatedly opened at the maximum opening and the minimum opening based on the temperature detected by the temperature sensor 37, and evaporates the ice making unit 11. The state of the liquefied refrigerant delivered to the vessel 34 is changed, and the cooling state of the ice making unit 11 is changed. When controlled in this way, the temperature of the ice making section 11 rises when the electronic expansion valve 33 is set to the maximum opening (increased opening) and is set to the minimum opening (decreased). The temperature can be lowered to make the gradient of the temperature decrease of the ice making section 11 gentle, and the temperature of the ice making section 11 can be slowly lowered in the vicinity of 0 ° C. As a result, it is possible to prevent the ice-making water frozen in the ice-making unit 11 from becoming supercooled and prevent the ice from becoming cloudy without stopping the water supply pump 25 and prolonging the time required for the ice-making operation. did it. Further, when the detection temperature of the ice making section 11 detected by the temperature sensor 37 becomes −5 ° C. or lower, the load for cooling the ice making water in the ice making section 11 is small, so that the control device 40 uses the electronic expansion valve 33. By reducing the opening degree of the ice-making unit 11, the ice-making unit 11 is cooled so that the ice-making water is frozen by the refrigerant whose opening degree is narrowed and the temperature is lowered.

The ice making section 11 is cooled in a state where the opening degree of the electronic expansion valve 33 is controlled based on the detection temperature of the temperature sensor 37, and the ice making water jetted and sent out from the ice making water tank 21 is gradually frozen in the ice making chamber 13. , The ice making water in the ice making water tank 21 gradually decreases. At this time, if the opening degree of the electronic expansion valve 33 is controlled so that the detection temperature of the temperature sensor 37 is −5 ° C. to −15 ° C., highly transparent ice with few cracks can be produced. The detection of the completion of ice making based on the detection temperature of the temperature sensor 37 is a unit which is the product of the detection temperature of the temperature sensor 37 detected every unit time from the time when the temperature of the ice making unit 11 reaches 0 ° C. and the unit time. When the total value obtained by obtaining the integrated value and sequentially adding these unit integrated values becomes the target integrated value, the control device 40 detects that block-shaped ice is formed in the ice making chamber 13 and the ice making is completed. The drive of the water supply pump 25 is stopped to end the ice making operation. By increasing the opening degree of the electronic expansion valve 33 from the timing immediately before the completion of ice making, it is possible to prevent the frozen ice from clinging to each ice making chamber 13.

In the deicing operation after the ice making operation, the control device 40 opens the hot gas valve 36 with the compressor 31 operated, and tilts the water pan 22 to the open position by the actuator motor 23a of the opening / closing mechanism 23. The hot gas sent from the compressor 31 is guided to the evaporator 34 through the hot gas pipe 35 to heat each ice making chamber 13 of the ice making section 11. The temperature of the ice making section 11 at the completion of ice making is about −20 ° C., but the ice is separated from the inside of the ice making chamber 13 while the temperature of the ice making section 11 gradually rises. When the detection temperature of the temperature sensor 37 becomes 5 ° C. or higher as a predetermined temperature for detecting that the deicing is completed, the control device 40 has no ice left in the ice making chamber 13 of the ice making section 11, that is, the deicing is completed. The hot gas valve 36 is closed to end the deicing operation, and the ice making operation is executed again as described above. In this way, by repeatedly executing the ice making operation and the deicing operation by the control device 40, the ice making unit 11 continuously produces block-shaped ice.

In the ice making machine 10 configured as described above, the ice making section 11 is provided with a temperature sensor 37, and the ice making section 11 is provided with an electronic expansion valve 33 whose opening degree is controlled based on the temperature detected by the temperature sensor 37. It is cooled by the freezing device 30. When the ice making operation is executed, the liquefied refrigerant pumped from the compressor 31 and liquefied by the condenser 32 is expanded by the electronic expansion valve 33 whose opening degree is controlled, and the expanded liquefied refrigerant is transferred to the evaporator 34. The ice making section 11 is cooled by the heat of vaporization, and the ice making water in the ice making water tank 21 is circulated and cooled between the ice making section 11 cooled by the refrigerating device 30, and the ice making water is cooled by the ice making section 11. It gradually freezes in the ice making chamber 13 and becomes ice. When the deicing operation is executed after the ice making operation, the hot gas valve 36 is opened to send the hot gas refrigerant sent from the compressor 31 to the evaporator 34 to heat the ice making section 11, and the ice making section 11 warms the ice. To leave. In this way, the ice maker 10 manufactures ice by alternately and repeatedly performing an ice making operation and an ice removing operation.

In the ice making machine 10, the control device 40 is provided with a temperature sensor 37 that detects the temperature of the ice making water via the ice making unit 11, and the detection temperature detected by the temperature sensor 37 during the ice making operation is the freezing of the ice making water. When the predetermined temperature before the start is 4 ° C., the opening of the electronic expansion valve 33 is controlled to be repeatedly opened (increased) at the maximum opening and opened (decreased) at the minimum opening. Therefore, the state of the liquefied refrigerant delivered to the evaporator 34 of the ice making section 11 is changed, and the cooling state of the ice making section 11 is changed. At this time, the control device 40 opens (increases) the electronic expansion valve 33 at the maximum opening degree (higher) and opens (lowers) the electronic expansion valve 33 at the minimum opening degree so as to make the gradient of the temperature decrease of the ice making unit 11 gentle. ) Is controlled. When controlled in this way, the temperature of the ice making section 11 rises when the electronic expansion valve 33 is opened at the maximum opening (increasing the opening), and is opened at the minimum opening (lowering the opening). Occasionally, the temperature of the ice making section 11 can be lowered to make the gradient of the temperature drop of the ice making section 11 gentle, and the temperature of the ice making section 11 can be slowly lowered in the vicinity of 0 ° C. As a result, it is possible to prevent the ice-making water frozen in the ice-making unit 11 from becoming supercooled and prevent the ice from becoming cloudy without stopping the water supply pump 25 and prolonging the time required for the ice-making operation. did it. Further, although the predetermined temperature before the start of freezing of the ice-making water is set to 4 ° C., the present invention is not limited to this, and the predetermined temperature is preferably in the range of 3 ° C. to 4 ° C. In this embodiment, when the detection temperature detected by the temperature sensor 37 during the ice making operation becomes 4 ° C. as the predetermined temperature before the start of freezing of the ice making water, the opening degree of the electronic expansion valve 33 is set to the maximum opening degree. It was controlled to repeat opening (increasing) and opening (lowering) at the minimum opening, but the present invention is not limited to this, and the opening of the electronic expansion valve 33 is opened to the maximum. It may be controlled so as to repeatedly open (increase) and close in degrees. Even in this case, the cooling state of the ice making section 11 can be changed, and the ice making water frozen in the ice making section 11 is excessive without stopping the water pump 25 and lengthening the time required for the ice making operation. It was possible to prevent the ice from becoming cold and to prevent the ice from becoming cloudy.

In the ice machine of this embodiment, a large number of downwardly open ice making chambers 13 provided in the ice making portion 11 are closed by a water tray 22 so as to be openable and closable, and ice making water is jetted and supplied from the water tray 22 to each ice making chamber 13. This is a so-called closed cell type ice maker that produces ice, but the present invention is not limited to this, and the present invention is a so-called open cell type ice maker that jets and supplies ice making water with the ice making chamber open. It may be an ice-making machine in which the ice-making chamber is opened in the horizontal direction and the ice-making water is allowed to flow down into the ice-making chamber, or the ice-making water is allowed to flow down on an ice-making plate that stands vertically. May be good.

10 ... Ice maker, 11 ... Ice making section, 21 ... Ice making water tank, 25 ... Water pump, 31 ... Compressor, 32 ... Condenser, 33 ... Electronic expansion valve, 34 ... Evaporator, 37 ... Temperature sensor, 40 ... Control Device.

Claims (4)

The ice making department that freezes ice making water to produce ice,
An ice-making water tank that stores ice-making water that is circulated and supplied to and from the ice-making part,
A water pump that sends the ice-making water in the ice-making water tank to the ice-making part,
A compressor that compresses the refrigerant, a condenser that cools and liquefies the refrigerant pumped from the compressor, an electronic expansion valve that expands the liquefied refrigerant liquefied by the condenser, and an electronic expansion valve that expands. A refrigerating apparatus having an evaporator that vaporizes the liquefied refrigerant and cools the ice making section.
A control device for controlling the operation of the water pump and the refrigerating device is provided.
In the ice making operation of producing ice in the ice making section, the liquefied refrigerant pumped from the compressor and liquefied by the condenser is expanded by the electronic expansion valve whose opening degree is controlled by the control device to expand. The ice making section is cooled by the heat of vaporization of the liquefied refrigerant vaporized by the evaporator.
While cooling the ice-making water delivered by the water supply pump in the cooled ice-making section, unfrozen ice-making water is collected in the ice-making water tank, and the ice-making water is gradually frozen in the ice-making section to produce ice. It ’s a machine,
A temperature sensor that detects the temperature of ice-making water is provided.
The control device is characterized in that when the detection temperature detected by the temperature sensor reaches a predetermined temperature before the start of freezing of the ice-making water, the opening degree of the electronic expansion valve is repeatedly increased and decreased. Ice machine. In the ice machine according to claim 1.
When the detection temperature detected by the temperature sensor reaches a predetermined temperature before the start of freezing of the ice-making water, the electronic expansion valve is controlled to repeat the maximum opening and the minimum opening or closing. Ice machine to do. In the ice machine according to claim 1 or 2.
When the detection temperature detected by the temperature sensor reaches a predetermined temperature before the start of freezing of the ice making water, the opening degree of the electronic expansion valve is increased or decreased so as to make the gradient of the temperature decrease of the ice making portion gentle. An ice maker characterized by being controlled to repeat the above. In the ice maker according to any one of claims 1 to 3.
An ice maker, characterized in that the temperature is set to 3 ° C. to 4 ° C. as a predetermined temperature before the start of freezing of the ice making water.

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