JP2019190751A - Ice making machine - Google Patents

Abstract

To reduce a difference in size of a recess generating at a lower part of ice growing in each ice making small chamber, while keeping a refrigerant which did not completely evaporate in an evaporator from returning to a compressor, in an ice making machine for producing ice in each ice making small chamber in a state of closing a plurality of ice making small chambers opening downward being closed by a water tray.SOLUTION: An ice making machine 10 recovers, in an ice making water tank 21, unfrozen ice making water while cooling the ice making water jetted and delivered by a water delivery pump 25 into ice making small chambers 13 in the ice making small chambers 13, and manufactures ice by gradually freezing the ice making water while circulating the ice making water between the ice making water tank 21 and ice making small chambers 13. A temperature sensor 38 is provided for detecting the temperature of an ice making part 11. A control device controls an opening of an electronic expansion valve 33 based on the detection temperature of the temperature sensor 38 so that it becomes the opening of the electronic expansion valve 33 set corresponding to the temperature of the ice making part 11.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an ice making machine that manufactures ice in each ice making chamber in a state where a number of ice making chambers opening downward in an ice making unit are closed by a water dish.

  Patent Document 1 discloses an ice making section having a large number of ice making chambers that open downward, an ice making water tank that stores ice making water supplied to each ice making chamber of the ice making section, and ice making water in the ice making water tank. There is disclosed an ice making machine including a water supply pump for jetting and feeding and a freezing device for cooling and heating an ice making unit. The ice making machine refrigeration apparatus includes 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, An evaporator that evaporates the liquefied refrigerant expanded by the electronic expansion valve and cools the ice making unit, a hot gas path that sends hot gas from the compressor to the evaporator, and a hot gas valve that is interposed in the hot gas path have.

  When the ice making operation is performed with this ice making machine, the refrigerant pumped from the compressor is cooled and liquefied by the condenser, and the liquefied refrigerant is vaporized by the evaporator while being expanded by the electronic expansion valve. Is cooled by the heat of vaporization of the refrigerant vaporized by the evaporator. The ice making water sprayed and delivered by the water pump into the ice making chamber of the ice making unit is cooled in the ice making chamber, unfrozen ice making water is collected in the ice making water tank, and the ice making water circulates between the ice making water tank and the ice making chamber. While cooling, it gradually freezes to become ice. The electronic expansion valve of the refrigeration system is controlled based on the temperature difference between the outlet temperature sensor and the inlet temperature sensor provided at the outlet and inlet of the evaporator, and increases the opening when the temperature difference increases. However, when the temperature difference is small, the opening degree is controlled to be small.

JP-A-10-339533

  In the ice making machine of Patent Document 1, the electronic expansion valve of the refrigeration apparatus is controlled based on the temperature difference between the outlet temperature sensor and the inlet temperature sensor provided at the outlet and inlet of the evaporator, and the temperature difference Control is performed such that the opening degree is increased when the temperature difference is increased, and the opening degree is decreased when the temperature difference is decreased. An ice making chamber in which the inlet portion of the evaporator is disposed when the opening of the electronic expansion valve is controlled so that the temperature difference between the outlet portion temperature sensor and the inlet portion temperature sensor is constant, for example, 5 ° C. to 10 ° C. And the ice making chamber where the outlet part of the evaporator is located, and the size of the dent that occurs in the lower part of the ice growing in the ice making chamber is arranged between the inlet part and the outlet part of the evaporator. There was a difference in the position.

  The ice making machine of Patent Document 1 is to inject and send ice making water in an ice making water tank to a large number of ice making chambers opening downward in an ice making unit, and freeze ice making water in the ice making chamber to produce ice. This type of ice making machine is a so-called open cell type ice making machine that produces ice with the lower opening of the ice making chamber open, and ice is produced with the lower opening of the ice making chamber closed by a water dish. There is a so-called closed cell type ice making machine. In the case of an open cell type ice making machine, since the lower opening of the ice making chamber is not closed, the shape of the lower portion of the ice grown in the ice making chamber is not constant as shown in FIG. The difference in the size of the dent generated in the lower part of the small room was not a problem.

  On the other hand, in the closed cell type ice making machine, since the lower opening of the ice making chamber is closed by the water tray, the shape of the lower portion of the ice grown in the ice making chamber is constant as shown in FIG. Therefore, the difference in the size of the dent generated in the lower part of the ice grown in the ice making chamber has become a quality problem. If the opening of the electronic expansion valve is controlled so that the temperature difference between the outlet temperature sensor and the inlet temperature sensor is lower than 5 ° C., for example, the difference in the size of the dent generated in the lower part of the ice growing in the ice making chamber Can be reduced at the position where the inlet and outlet of the evaporator are arranged. However, if the temperature difference between the outlet temperature sensor and the inlet temperature sensor is set low and the opening degree of the electronic expansion valve is controlled, excessive refrigerant may be supplied to the evaporator, and the evaporator can completely evaporate. There was a possibility that a so-called liquid back may occur in which the refrigerant that was not returned returns to the compressor. Also, when the opening of the electronic expansion valve is controlled by the temperature difference between the outlet temperature sensor and the inlet temperature sensor, it is difficult to determine whether a liquid back has occurred, and there is insufficient refrigerant circulating in the refrigeration system, or the compressor However, there is a risk of failure due to so-called liquid back. The present invention is an ice making machine that manufactures ice in each ice making chamber in a state where a number of ice making chambers that open downward are closed by water trays, so that refrigerant that cannot be evaporated by the evaporator does not return to the compressor. On the other hand, the object is to reduce the difference in the size of the dents generated in the lower part of the ice growing in each ice making chamber.

  In order to solve the above-mentioned problems, the present invention provides an ice making unit having a large number of ice making chambers that open downward, and a water dish that is disposed below the ice making unit and closes the lower opening of the ice making chamber so as to be openable and closable. An ice making water tank for storing ice making water to be supplied to each ice making chamber of the ice making unit, a water supply pump for injecting and sending the ice making water in the ice making water tank to the ice making chamber, a freezing device for cooling and heating the ice making unit, The refrigeration apparatus includes a compressor that compresses the refrigerant, a condenser that cools and liquefies the refrigerant pumped from the compressor, and a liquefaction by the condenser. In an ice making operation that has an electronic expansion valve that expands the liquefied refrigerant and an evaporator that evaporates the liquefied refrigerant expanded by the electronic expansion valve and cools the ice making unit, Liquefaction that was pumped from and liquefied with a condenser The medium is expanded by an electronic expansion valve whose opening degree is controlled by a control device, the ice making part is cooled by the heat of vaporization of the expanded liquefied refrigerant vaporized by an evaporator, and the water is pumped into the ice making chamber The ice making machine collects unfrozen ice making water in an ice making water tank while cooling the ice making water in the ice making room, and gradually freezes the ice making water in the ice making room to produce ice, the temperature of the ice making unit The control device controls the opening degree of the electronic expansion valve based on the temperature detected by the temperature sensor so that the opening degree of the electronic expansion valve is set corresponding to the temperature of the ice making unit. An ice making machine characterized by the above is provided.

  In the ice making machine configured as described above, a temperature sensor that detects the temperature of the ice making unit is provided, and the control device sets the temperature of the electronic expansion valve so as to correspond to the temperature of the ice making unit. The opening degree of the electronic expansion valve was controlled based on the temperature detected by the sensor. The position where the inlet and outlet of the evaporator are arranged to prevent the refrigerant from returning from the evaporator to the compressor in a liquefied state, and the difference in the size of the dent generated in the lower part of the ice growing in the ice making chamber The opening of the electronic expansion valve is set in advance corresponding to the temperature of the ice making unit, and the opening of the electronic expansion valve is controlled based on the temperature of the ice making unit so that the The refrigerant is prevented from returning to the compressor in a liquefied state, and the difference in the size of the dent generated at the bottom of the ice growing in the ice making chamber is reduced at the position where the inlet and outlet portions of the evaporator are arranged. I was able to. In particular, since the opening degree of the electronic expansion valve is not controlled based on the temperature difference between the outlet and inlet of the evaporator in the ice making unit, the time lag when detecting the temperature between the outlet and inlet of the evaporator The effect of reducing the difference in the size of the dent generated at the bottom of the ice growing in each ice making chamber can be reliably prevented without being influenced by the above. In the ice making machine configured as described above, the temperature sensor preferably detects the temperature of the outlet of the refrigerant in the evaporator in the ice making unit.

  In the ice making machine configured as described above, the set opening degree of the electronic expansion valve is set to be an opening degree reduction rate corresponding to a temperature drop of the ice making part, and the opening degree reduction rate is the temperature of the ice making part. It is preferably set so as to change in three steps or more depending on the range. In this case, the temperature range of the ice making unit includes the temperature range of the cooling stage in which the ice making water jetted and sent into the ice making chamber is cooled before freezing in the ice making chamber, and the start of freezing in which the ice making water starts to freeze in the ice making chamber It is preferable to include the temperature range in the stage and the temperature range in the ice growth stage in which ice is grown in the ice making chamber. Since the opening reduction rate according to the temperature drop of the ice making part is changed according to the state of the ice making water, the refrigerant according to the state of the ice making water can be sent to the ice making part.

  In addition, since ice making water is accompanied by a phenomenon such as supercooling when it begins to freeze in the ice making chamber, the temperature of the ice making part may rise temporarily. When the temperature of the ice making part rises temporarily, the temperature difference between the outlet part and the inlet part of the evaporator also increases, and when the opening of the electronic expansion valve is controlled to increase, the outlet part of the evaporator Even if the temperature difference at the inlet is reduced and the opening of the electronic expansion valve is controlled to be reduced again, it takes time for the temperature at the outlet of the evaporator to change as the opening of the electronic expansion valve is reduced. As a result, the refrigerant returns from the evaporator to the compressor in a liquefied state. Since the cooling capacity is reduced by returning the refrigerant to the compressor in the liquefied state, and the opening of the electronic expansion valve is controlled to be reduced again, the temperature difference between the outlet portion and the inlet portion of the evaporator is reduced. It grows again. In this way, by repeatedly increasing and decreasing the opening of the electronic expansion valve, the vertical movement of the temperature difference between the outlet portion and the inlet portion of the evaporator gradually increases and the ice making portion cannot be cooled. There was a fear.

  On the other hand, in the ice making machine configured as described above, the control device maintains the opening degree of the electronic expansion valve without changing when the temperature detected by the temperature sensor rises, and the temperature detected by the temperature sensor is not changed. When the temperature drops again to the temperature corresponding to the opening of the electronic expansion valve when maintained without change, the control to the opening of the electronic expansion valve set corresponding to the temperature of the ice making part is resumed. Is preferred. When this is done, the temperature of the electronic expansion valve is maintained without change when the temperature fluctuation starts as the temperature of the ice making unit rises, such as when ice making water begins to freeze in the ice making chamber. By doing so, it is possible to prevent unnecessary adjustment of the opening of the electronic expansion valve, and it is possible to prevent the refrigerant from returning from the evaporator to the compressor in a liquefied state. In addition, when the detected temperature of the temperature sensor reaches a temperature corresponding to the opening of the electronic expansion valve when the opening is maintained without changing the opening, the electronic expansion valve set corresponding to the detected temperature of the temperature sensor The temperature sensor detection is performed so that the opening of the electronic expansion valve is set according to the temperature of the ice making part after the temperature fluctuation of the ice making part is finished. The opening degree of the electronic expansion valve can be controlled based on the temperature.

  In another embodiment of the present invention, an ice making unit having a large number of ice making chambers that open downward, and a water dish that is disposed below the ice making unit and closes an opening at the bottom of the ice making chamber so as to be freely opened and closed. An ice making water tank for storing ice making water to be supplied to each ice making chamber of the ice making unit, a water supply pump for injecting and sending ice making water in the ice making water tank from below into the ice making chamber, a refrigeration apparatus for cooling the ice making unit, The refrigeration apparatus includes a compressor that compresses the refrigerant, a condenser that cools and liquefies the refrigerant pumped from the compressor, and a liquefaction by the condenser. In an ice making operation that has an electronic expansion valve that expands the liquefied refrigerant and an evaporator that evaporates the liquefied refrigerant expanded by the electronic expansion valve and cools the ice making unit, Liquefaction that was pumped from and liquefied with a condenser The medium is expanded by an electronic expansion valve whose opening degree is controlled by a control device, the ice making part is cooled by the heat of vaporization of the expanded liquefied refrigerant vaporized by an evaporator, and the water is pumped into the ice making chamber The ice making water is cooled in the ice making chamber while unfrozen ice making water is collected in the ice making water tank, and the ice making water is circulated between the ice making water tank and the ice making chamber to gradually freeze to produce ice. The refrigeration apparatus has a first connection line that connects the condenser and the electronic expansion valve, and a second connection line that connects the evaporator and the compressor, and the first connection line And an electronic expansion valve temperature sensor for detecting the inlet temperature of the electronic expansion valve, and the control device is based on the detected temperature of the electronic expansion valve temperature sensor. Ice making machine characterized by controlling the opening of the electronic expansion valve It is intended to provide.

  In the ice making machine configured as described above, the refrigeration apparatus has a first connection line that connects the condenser and the electronic expansion valve, and a second connection line that connects the evaporator and the compressor. The first connection pipe line and the second connection pipe line are arranged in a state in which heat exchange is possible with each other, and an electronic expansion valve temperature sensor for detecting an inlet temperature of the electronic expansion valve is provided. The opening degree of the electronic expansion valve was controlled based on the temperature detected by the sensor. The heat of the second connecting pipe from which the refrigerant returns from the evaporator to the compressor is transferred to the first connecting pipe that sends the refrigerant from the condenser to the electronic expansion valve. The refrigerant that does not evaporate in the evaporator returns to the compressor in a liquefied state through the second connection pipe, and the liquefied refrigerant that passes through the second connection pipe cools the refrigerant sent to the electronic expansion valve through the first connection pipe. Will do. Electronic expansion is controlled so that the refrigerant does not return from the evaporator to the compressor in a liquefied state by controlling the opening of the electronic expansion valve based on the temperature detected by the electronic expansion valve temperature sensor that detects the temperature of the inlet of the electronic expansion valve. The valve opening can now be controlled. In addition, the ice making machine is provided with a temperature sensor that detects the temperature of the ice making unit, and the control device controls the opening degree of the electronic expansion valve based on the detected temperature of the electronic expansion valve temperature sensor and the detected temperature of the temperature sensor. In this case, the opening degree of the electronic expansion valve can be accurately controlled so that the refrigerant does not return from the evaporator to the compressor in a liquefied state.

1 is a schematic view of an ice making machine according to the present invention. It is a block diagram of a control apparatus. It is the graph which showed the relationship between the temperature of an ice making part, and the opening degree of an electronic expansion valve. It is a graph which shows the temperature change of the ice making part when performing the ice making operation. It is the schematic of the ice maker of other embodiment. It is the schematic (a) of the shape of the ice manufactured in an open cell type ice making chamber, and the schematic view (b) of the shape of the ice manufactured in a closed cell type ice making chamber.

  Hereinafter, an embodiment of an ice making machine of the present invention will be described with reference to the drawings. As shown in FIG. 1, the ice making machine 10 closes a number of ice making chambers 13 provided in the ice making unit 11 that open downward by a water tray 22 so that the ice making chambers 13 can be opened and closed. This is a so-called closed cell type ice making machine that produces ice by jetting water. The ice making machine 10 produces ice by alternately executing an ice making operation in which 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. is there. The ice making machine 10 employs an electronic expansion valve 33 whose opening can be adjusted by the control of the control device 40 as an expansion valve of the refrigeration apparatus 30, and appropriately controls the opening of the electronic expansion valve 33. Thus, while preventing the refrigerant that could not be evaporated by the evaporator 34 from returning to the compressor 31, the difference in the size of the dent generated in the lower part of the ice growing in each ice making chamber 13 was made as small as possible. Is.

  The ice making unit 11 has a shallow box shape that is horizontally arranged and opened on the lower side, and a plurality of ice making chambers 13 opened downward by the partitioning member 12 are formed. Further, below the ice making unit 11, an ice storage 14 for storing ice produced in each ice making chamber 13 is provided.

  The ice making 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 tray 22 integrally provided with an ice making water tank 21 at a lower portion. The water tray 22 approaches the lower side of the ice making unit 11 and closes the lower opening of the ice making chamber 13, and the open position that opens away from the lower side of the ice making unit 11 and opens the lower opening of the ice making chamber 13. It is supported so that it can tilt between. The water tray 22 is provided with an open / close mechanism 23 that tilts between a closed position and an open position, and the water tray 22 opens and closes the lower opening of the ice making chamber 13 of the ice making unit 11 by the open / close mechanism 23. The opening / closing mechanism 23 includes an actuator motor 23a, and tilts the water tray 22 between a closed position and an open position by driving the actuator motor 23a.

  The water supply section 20 is provided with a water supply means 24 for supplying ice making water to the ice making water tank 21 and a water supply pump 25 for injecting and sending 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. The ice-making water sent from the water supply pipe 24a is opened by opening the water supply valve 24b. 21 is supplied. The ice making water supplied to the ice making water tank 21 is jetted out to the ice making chamber 13 by the water pump 25.

  As shown in FIG. 1, the ice making machine 10 includes a refrigeration apparatus 30 that cools and heats the ice making unit 11. The refrigeration apparatus 30 includes a compressor 31 that compresses the refrigerant, a condenser 32 that cools and liquefies the refrigerant pumped from the compressor 31, and expands the liquefied refrigerant liquefied by the condenser 32 to liquefy the refrigerant at a low pressure. An electronic expansion valve 33 serving as a refrigerant, and an evaporator 34 that evaporates the liquefied refrigerant expanded by the electronic expansion valve 33 and cools the ice making unit 11 are provided. In the refrigeration apparatus 30, a compressor 31, a condenser 32, an electronic expansion valve 33, and an evaporator 34 are annularly connected by a connecting pipe 35 (35a to 35d) to constitute a refrigeration circuit. The electronic expansion valve 33 can be adjusted in opening degree by a control signal of the control device 40 described later. The evaporator 34 uses a pipe material having high thermal conductivity such as a copper pipe, and is meanderingly arranged on the upper surface of the ice making unit 11. The ice making unit 11 is cooled by the heat of vaporization when the liquefied refrigerant passing through the evaporator 34 is vaporized. The connecting pipe 35 includes a connecting pipe 35 a that connects the compressor 31 and the condenser 32, a connecting pipe (first connecting pipe) 35 b that connects the condenser 32 and the electronic expansion valve 33, and an electronic expansion valve. 33 and a connection pipe 35 c that connects the evaporator 34 and a connection pipe (second connection pipe) 35 d that connects the evaporator 34 and the compressor 31. A connection line (second connection line) for connecting the heat exchanger 35b1 of the connection line (first connection line) 35b connecting the condenser 32 and the electronic expansion valve 33, the evaporator 34, and the compressor 31. The heat exchange part 35d1 of 35d is arrange | positioned in the state which can be heat-exchanged by making it contact.

  The refrigeration apparatus 30 includes a hot gas pipe (hot gas path) 36 that supplies hot gas to the evaporator 34 during the deicing operation. The hot gas pipe 36 connects the downstream of the compressor 31 and the upstream of the evaporator 34 so as to guide the hot gas from the compressor 31 to the evaporator 34. A hot gas valve 37 is interposed in the hot gas pipe 36, and hot gas sent from the compressor 31 is guided to the evaporator 34 through the hot gas pipe 36 when the hot gas valve 37 is opened. When the hot gas is guided to the evaporator 34 by opening the hot gas valve 37 during the deicing operation, the ice making chamber 13 of the ice making unit 11 is heated by the hot gas, and the ice frozen in the ice making chamber 13 is deiced. Is done.

The ice making section 11 is provided with an outlet temperature sensor (temperature sensor) 38 at the refrigerant outlet 34 a of the evaporator 34, and the outlet temperature sensor 38 is connected to the refrigerant outlet section 34 a of the evaporator 34 in the ice making section 11. Detect temperature. The outlet temperature sensor 38 is not only used for controlling the opening degree of the electronic expansion valve 33 during ice making operation, but also completes ice making during ice making operation and deicing when performing ice removal operation. Used to detect completion of
The ice making machine 10 includes a control device 40. 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 supply pump 25, and a compressor 31 of the refrigeration device 30. The hot gas valve 37 and the outlet temperature sensor 38 are connected. The control device 40 includes a microcomputer (not shown), and the microcomputer includes a CPU, a RAM, a ROM, and a timer (all not shown) connected via a bus. The control device 40 executes an ice making program for repeatedly executing an ice making operation for producing ice by freezing ice making water in the ice making unit 11 and an ice removing operation for removing ice frozen in the ice making unit 11 by the ice making operation. Have.

  As shown in FIG. 3, when the ice making operation of the ice making program is performed, the control device 40 sets the electronic expansion valve set corresponding to the temperature of the refrigerant outlet portion 34 a (the temperature of the ice making portion 11) of the evaporator 34. The opening degree of the electronic expansion valve 33 is controlled based on the temperature detected by the outlet temperature sensor 38 so that the opening degree becomes 33. The opening degree of the electronic expansion valve 33 set in advance corresponding to the temperature of the refrigerant outlet part 34a of the evaporator 34 is an opening degree reduction rate corresponding to the temperature drop of the refrigerant outlet part 34a of the evaporator 34. Is set to In this embodiment, the degree of opening reduction according to the temperature drop of the refrigerant outlet 34 a of the evaporator 34 is set to change in three stages according to the temperature range of the refrigerant outlet 34 a of the evaporator 34. .

  The set temperature range changes according to the cooling stage of the ice making water. In this embodiment, the temperature range is divided into first to third temperature ranges, and the first temperature range is a cooling stage in which the ice making water sprayed into the ice making chamber 13 is cooled in the ice making chamber 13 before freezing. The second temperature range is a temperature range at the start of freezing in which ice making water begins to freeze in the ice making chamber 13, and the third temperature range is ice in which ice grows in the ice making chamber 13. The temperature range is in the growth stage.

  The first temperature range is a temperature range for cooling normal temperature water supplied into the ice making water tank 21 so that it can be frozen in the ice making chamber 13. When the temperature is within the first temperature range, the temperature of the ice making water is lowered. Therefore, a large amount of refrigerant is required. For this reason, the first temperature range is set so that the temperature of the outlet 34a of the evaporator 34 is not less than t1 ° C. When the temperature is within the first temperature range, the opening degree of the electronic expansion valve 33 is set to a1 (for example, 70 to 70). 90%).

  The second temperature range is a temperature range when the ice making water cooled in the cooling stage starts to freeze in the ice making chamber 13, and a larger amount of refrigerant is not required in the second temperature range than in the first temperature range. However, when the ice making water begins to freeze, it is necessary to reduce the flow rate of the refrigerant. For this reason, the second temperature range is set such that the temperature of the outlet 34a of the evaporator 34 is in the range of t2 to t1 ° C. When the temperature is within the second temperature range, the opening degree of the electronic expansion valve 33 is gradually decreased from a1 to a2. It is trying to become.

  The third temperature range is a temperature range when growing ice that has started to freeze in the ice making chamber 13, and the flow rate of the refrigerant is gently reduced in the third temperature range than in the second temperature range. There is a need. For this reason, the third temperature range is set so that the temperature of the outlet 34a of the evaporator 34 is in the range of t3 to t2 ° C., and the opening degree of the electronic expansion valve 33 is more in the third temperature range than in the second temperature range. It is made to become small gently from a2 to a3.

  When the opening a2 of the electronic expansion valve 33 at the temperature t2 of the outlet 34a of the evaporator 34 set in the second and third temperature ranges is used as a reference, the temperature is set in the first and second temperature ranges. The opening a1 of the electronic expansion valve 33 at the temperature t1 of the outlet portion 34a of the evaporator 34 is 1.5 times or more of a2, and the outlet portion 34a of the evaporator 34 set in the third temperature range. The opening degree a3 of the electronic expansion valve 33 at the temperature t3 is set to 0.5 times or less of a2.

  Next, an ice making program of the ice making machine 10 will be described. When the ice making machine 10 is started, a deicing operation is preliminarily executed to make sure that no ice remains in the ice making chamber 13 of the ice making unit 11. In the deicing operation, the hot gas valve 37 is opened while the compressor 31 is operated, and the water dish 22 is tilted to the open position by the actuator motor 23 a of the opening / closing mechanism 23. The hot gas delivered from the compressor 31 is guided to the evaporator 34 through the hot gas pipe 36 to heat each ice making chamber 13 of the ice making unit 11. When the detected temperature of the outlet temperature sensor 38 reaches 5 ° C. or more as a predetermined temperature for detecting that the deicing is completed, the control device 40 indicates that no ice remains in the ice making chamber 13 of the ice making unit 11, that is, deicing is not performed. When it is detected that it is completed, the hot gas valve 37 is closed and the deicing operation is terminated.

  After executing the deicing operation in advance in the ice making unit 11, the control device 40 repeatedly executes the ice making operation and the deicing operation in the ice making unit 11. In the ice making operation, the control device 40 tilts the water tray 22 to the closed position by the actuator motor 23a of the opening / closing mechanism 23 and supplies the ice making water to the ice making water tank 21 by opening the water supply valve 24b for a predetermined time. Next, the control device 40 closes the water supply valve 24b after a predetermined time has elapsed to end the water supply, and drives the water supply pump 25 to inject and send the ice making water in the ice making water tank 21 to each ice making chamber 13 of the ice making unit 11. Let

  The ice making unit 11 is cooled by the refrigeration apparatus 30 by closing the hot gas valve 37 at the end of the deicing operation as well as supplying water from the water supply pipe 24 a to the ice making water tank 21. Specifically, the refrigerant pumped from the compressor 31 is liquefied by the condenser 32 to become a liquefied refrigerant, and the liquefied refrigerant is an electron whose opening degree is adjusted by the control device 40 based on the temperature detected by the outlet temperature sensor 38. The low pressure liquefied refrigerant expands by the expansion valve 33 and is vaporized by the evaporator 34 to cool the ice making unit 11. The ice making water sprayed and delivered to the ice making chamber 13 by the water pump 25 is cooled and frozen in the ice making chamber 13, and the ice making water in the ice making water tank 21 gradually decreases. When the ice making operation is performed, the control device 40, as described above, the outlet temperature sensor 38 so that the opening degree of the electronic expansion valve 33 is set corresponding to the temperature of the outlet 34a of the refrigerant of the evaporator 34. The opening degree of the electronic expansion valve 33 is controlled based on the detected temperature.

  In the deicing operation after the ice making operation, the control device 40 opens the hot gas valve 37 with the compressor 31 operated, and tilts the water tray 22 to the open position by the actuator motor 23a of the opening / closing mechanism 23. The hot gas delivered from the compressor 31 is guided to the evaporator 34 through the hot gas pipe 36 to heat each ice making chamber 13 of the ice making unit 11. Although the temperature of the ice making unit 11 at the time of completion of ice making is about −20 ° C., the ice is detached from the ice making chamber 13 while the temperature of the ice making unit 11 gradually increases. When the detected temperature of the outlet temperature sensor 38 reaches 5 ° C. or more as a predetermined temperature for detecting that the deicing is completed, the control device 40 indicates that no ice remains in the ice making chamber 13 of the ice making unit 11, that is, deicing is not performed. When it is detected that it has been completed, the hot gas valve 37 is closed, the deicing operation is terminated, and the ice making operation is executed again as described above. In the ice making machine 10, block-type ice is manufactured in the ice making unit 11 by repeatedly executing the ice making operation and the deicing operation by the control device 40.

  The ice making machine 10 configured as described above is provided with an outlet temperature sensor 38 that detects the temperature of the ice making unit 11, particularly the temperature of the outlet 34a of the refrigerant of the evaporator 34 in the ice making unit 11, and the control device 40 includes: Based on the temperature detected by the outlet temperature sensor 38, the electronic expansion valve 33 is adjusted so that the opening of the electronic expansion valve 33 is set in accordance with the temperature of the refrigerant outlet 34 a of the evaporator 34 in the ice making unit 11. The opening was controlled.

  The degree of opening of the electronic expansion valve 33 set corresponding to the temperature of the refrigerant outlet 34a is such that the refrigerant does not return from the evaporator 34 to the compressor 31 in a liquefied state, while the outlet 34a of the evaporator 34 The ice making chamber 13 in which the outlet 34a of the evaporator 34 is disposed is sufficiently cooled so that the liquefied refrigerant is not insufficient, and the difference in the size of the dent generated in the lower part of the ice growing in the ice making chamber 13 is evaporated. The inlet 34 and the outlet 34a of the container 34 are made small at the position where they are arranged. The refrigerant is liquefied from the evaporator 34 to the compressor 31 by controlling the opening of the electronic expansion valve 33 based on the temperature detected by the outlet temperature sensor 38 so that the opening is set in advance. It was possible to make the lower shape of the ice growing in each ice making chamber 13 as uniform as possible while preventing the return. In particular, since the opening degree of the electronic expansion valve 33 is not controlled based on the temperature difference between the inlet portion and the outlet portion 34a of the evaporator 34 in the ice making unit 11, the temperature at the inlet portion and the outlet portion 34a of the evaporator 34 is not controlled. The refrigerant is prevented from returning to the compressor 31 in the liquefied state without being affected by the time lag when detecting the ice, and the effect of making the shape of the lower part of the ice growing in each ice making chamber 13 uniform can be reliably obtained. I was able to.

  Further, the opening degree of the electronic expansion valve 33 set corresponding to the temperature of the outlet portion 34a of the evaporator 34 is set to be an opening degree reduction rate corresponding to the temperature drop of the outlet portion 34a of the evaporator 34. The opening reduction rate is set to change in three steps (three steps or more) according to the temperature range of the outlet 34a of the evaporator 34. The temperature range set to change the opening reduction rate includes the first temperature range in the cooling stage in which the ice making water jetted and sent into the ice making chamber 13 is cooled in the ice making chamber 13 before freezing, and the ice making chamber 13 The ice making water is divided into a second temperature range at the freezing start stage and a third temperature range at the ice growing stage in which ice is grown in the ice making chamber 13.

  In the first temperature range, a large amount of refrigerant is required to lower the temperature of the ice making water, so that the opening degree of the electronic expansion valve 33 is kept constant at a high level. In this case, the opening reduction rate is 0, but the present invention is not limited to this, and the opening may be lowered with a very low opening reduction rate. In the second temperature range, since the ice making water starts to freeze in the ice making chamber 13, it is necessary to gradually reduce the flow rate of the refrigerant, and the opening degree of the electronic expansion valve 33 is gradually lowered. Since the ice temperature grows in the ice making chamber 13 in the third temperature range, it is necessary to reduce the opening degree of the electronic expansion valve 33 over time, and the opening degree of the electronic expansion valve 33 is set to the second temperature range. The temperature is made lower than that in the temperature range. In this embodiment, the degree of decrease in the opening degree in the third temperature range is 1/5 of the opening degree reduction ratio in the second temperature range (1/3 to 1/6 depending on the type of ice machine). Is preferable). The rate of decrease in the degree of opening of the electronic expansion valve 33 according to the temperature drop at the outlet 34a (ice making part 11) of the evaporator 34 is determined based on the state of the ice making water (when the ice making water starts to freeze before the ice making water freezes) Therefore, it is possible to send the refrigerant according to the state of the ice making water to the ice making unit 11. In this embodiment, the opening reduction rate is set to change in three stages according to the temperature range of the outlet 34a of the evaporator 34. However, the present invention is not limited to this, and the opening reduction rate is set to the evaporator. It may be set so as to change in three or more steps according to the temperature range of the 34 outlet portions 34a.

  Further, as shown by a two-dot chain line in FIG. 4, since the ice making water is accompanied by a phenomenon such as supercooling when it begins to freeze in the ice making chamber 13, the temperature of the ice making unit 11 may rise temporarily. . When the temperature of the ice making unit 11 temporarily rises, the temperature difference between the outlet 34a and the inlet of the evaporator 34 also temporarily increases, and the opening degree of the electronic expansion valve 33 is controlled to be increased. In addition, the temperature difference between the outlet 34a and the inlet of the evaporator 34 is reduced. At this time, even if the opening degree of the electronic expansion valve 33 is controlled to be reduced again, it takes time until the temperature of the outlet portion 34a of the evaporator 34 is changed by reducing the opening degree of the electronic expansion valve 33. Therefore, the refrigerant may return from the evaporator 34 to the compressor 31 in a liquefied state. Since the cooling capacity is reduced by returning the refrigerant to the compressor 31 in the liquefied state, and the opening degree of the electronic expansion valve 33 is controlled to be reduced again, the outlet portion 34a and the inlet portion of the evaporator 34 are controlled. The temperature difference increases. By repeatedly increasing and decreasing the opening of the electronic expansion valve 33, the vertical movement of the temperature difference between the outlet 34a and the inlet of the evaporator 34 gradually increases, and the ice making unit 11 cannot be cooled. There was a fear.

  On the other hand, in the ice making machine 10, as shown by the solid line in FIG. 4, the control device 40 does not change the opening degree of the electronic expansion valve 33 when the detected temperature of the outlet temperature sensor 38 increases. When the temperature detected by the outlet temperature sensor 38 is again lowered to a temperature corresponding to the opening of the electronic expansion valve 33 when the opening is maintained without changing the opening, the outlet 34a of the evaporator 34 described above. Control was performed so that the opening degree of the electronic expansion valve 33 was set corresponding to the temperature of the (ice-making unit 11). As a result, when the temperature fluctuation starts as the temperature of the ice making unit 11 rises as when the ice making water starts to freeze in the ice making chamber 13, the opening degree of the electronic expansion valve 33 is maintained without being changed. By doing so, it is possible to prevent the refrigerant from returning from the evaporator 34 to the compressor 31 in a liquefied state by preventing unnecessary adjustment of the opening of the electronic expansion valve 33. Further, when the temperature detected by the outlet temperature sensor 38 is not changed, the temperature of the outlet 34a (ice making unit 11) of the evaporator 34 is reached when the temperature corresponds to the opening of the electronic expansion valve 33. Since the control for resuming the opening of the electronic expansion valve 33 set corresponding to the above is resumed, the refrigerant is prevented from returning to the compressor 31 in the liquefied state even after the temperature fluctuation of the ice making unit 11 is finished. And the effect which makes uniform the lower shape of the ice which grows in each ice making chamber 13 was able to be acquired.

  The ice making machine 10 of the above embodiment is provided with an outlet temperature sensor 38 that detects the temperature of the outlet 34 a of the evaporator 34 as the ice making unit 11, and the control device 40 is set corresponding to the temperature of the ice making unit 11. The opening degree of the electronic expansion valve 33 is controlled based on the temperature detected by the outlet temperature sensor 38 so that the opening degree of the electronic expansion valve 33 becomes the same. The ice making machine 10A of the embodiment shown in FIG. 5 to be described next is provided with an electronic expansion valve temperature sensor 39 that detects the inlet temperature of the electronic expansion valve 33, and the control device 40 detects the electronic expansion valve temperature sensor 39. The opening degree of the electronic expansion valve 33 is controlled based on the temperature.

  As described above, the connection line (first connection line) that connects the heat exchanger 35b1 of the connection line (first connection line) 35b that connects the condenser 32 and the electronic expansion valve 33, the evaporator 34, and the compressor 31 (first connection line). (2 connecting pipes) are arranged in a state where heat exchange is possible by bringing them into contact with the heat exchange part 35d1 of the 35d. When the ice making operation of the ice making machine 10 is being executed, when the refrigerant does not evaporate in the evaporator 34, the refrigerant passes through the connection line (second connection line) 35d and is liquefied to the compressor 31. Return. The liquefied refrigerant passing through the connection pipe (second connection pipe) 35d cools the refrigerant passing through the connection pipe (first connection pipe) 35b, and the temperature detected by the electronic expansion valve temperature sensor 39 is lowered.

In this embodiment, the control device 40 controls the opening degree of the electronic expansion valve 33 based on the temperature detected by the electronic expansion valve temperature sensor 39. The opening degree X (%) of the electronic expansion valve 33 is calculated by the following equation as an example.
X (%) = T1 ² × K1 + K2
T1: Temperature detected by the electronic expansion valve temperature sensor 39 (° C.)
K1: Constant (different for each type of ice making machine, 0.05 in this embodiment)
K2: Constant (different for each ice machine model, 5 in this embodiment)
When the ice making water having a high temperature is cooled by the evaporator 34 as when the ice making operation is started, the temperature of the refrigerant returning to the compressor 31 through the connection line (second connection line) 35d is also high. The temperature of the refrigerant passing through the pipe line (first connection pipe line) 35b also increases. In this case, if the detected temperature of the electronic expansion valve temperature sensor 39 is 40 ° C., the opening degree of the electronic expansion valve 33 is calculated as 85%.
On the other hand, when the cooling load in the evaporator 34 is reduced as when the end of the ice making operation is approached, the temperature of the refrigerant returning to the compressor 31 through the connection line (second connection line) 35d. The temperature of the refrigerant passing through the connection pipe line (first connection pipe line) 35b is also low. In this case, if the detected temperature of the electronic expansion valve temperature sensor 39 is 10 ° C., the opening degree of the electronic expansion valve 33 is calculated as 10%.

  When the refrigerant returns from the evaporator 34 to the compressor 31 in a liquefied state during the ice making operation, the refrigerant passing through the connection line (first connection line) 35b is connected to the connection line (second connection line). ) It is cooled rapidly by the liquefied refrigerant returning to the compressor 31 through 35d. In this case, when the temperature detected by the electronic expansion valve temperature sensor 39 is lowered to, for example, 20 ° C., the opening degree of the electronic expansion valve 33 is calculated as 25% from the above formula. By restricting the opening of the electronic expansion valve 33 to 25%, the amount of liquefied refrigerant supplied to the evaporator 34 is reduced, and the liquefied refrigerant supplied to the evaporator 34 is not subjected to heat exchange with ice-making water, and the compressor. Therefore, the refrigerant can be prevented from returning from the evaporator 34 to the compressor 31 in a liquefied state.

In this embodiment, the control device 40 may control the opening degree of the electronic expansion valve 33 based on the detected temperature of the electronic expansion valve temperature sensor 39 and the detected temperature of the outlet portion temperature sensor 38. The opening degree X (%) of the electronic expansion valve 33 in this case is calculated by the following equation as an example.
X (%) = T1 × (T2 + K3) × K4 + K5
T1: Temperature detected by the electronic expansion valve temperature sensor 39 (° C.)
T2: Temperature detected by the outlet temperature sensor 38 (° C.)
K3: Constant (different for each ice machine model, 20 in this embodiment)
K4: Constant (varies depending on the type of ice machine, and is 0.04 in this embodiment)
K5: Constant (varies depending on the type of ice making machine, 20 in this embodiment)
When the ice making water having a high temperature is cooled by the evaporator 34 as when the ice making operation is started, the temperature of the refrigerant returning to the compressor 31 through the connection line (second connection line) 35d is also high. The temperature of the refrigerant passing through the pipe line (first connection pipe line) 35b also increases. In this case, if the detected temperature of the electronic expansion valve temperature sensor 39 is 40 ° C. and the detected temperature of the outlet temperature sensor 38 is 20 ° C., the opening degree of the electronic expansion valve 33 is calculated as 84%.

  On the other hand, when the cooling load in the evaporator 34 is reduced as when the end of the ice making operation is approached, the temperature of the refrigerant returning to the compressor 31 through the connection line (second connection line) 35d. The temperature of the refrigerant passing through the connection pipe line (first connection pipe line) 35b is also low. In this case, if the detected temperature of the electronic expansion valve temperature sensor 39 is 10 ° C. and the detected temperature of the outlet temperature sensor 38 is −20 ° C., the opening degree of the electronic expansion valve 33 is calculated as 20%. When the opening degree of the electronic expansion valve 33 is controlled based on the detected temperature of the electronic expansion valve temperature sensor 39 and the detected temperature of the outlet temperature sensor 38, it is based only on the detected temperature of the electronic expansion valve temperature sensor 39. Thus, the opening degree of the electronic expansion valve 33 can be controlled more gently than when the opening degree of the electronic expansion valve 33 is controlled.

  Further, even when the opening degree of the electronic expansion valve 33 is controlled based on the detected temperature of the electronic expansion valve temperature sensor 39 and the detected temperature of the outlet temperature sensor 38 in the ice making operation, the opening degree of the electronic expansion valve 33 is set. The amount of liquefied refrigerant supplied to the evaporator 34 is reduced so as to reduce the amount of liquefied refrigerant supplied to the evaporator 34 so that the liquefied refrigerant supplied to the evaporator 34 does not exchange heat with ice-making water and return to the compressor 31. Returning from the evaporator 34 to the compressor 31 in a liquefied state can be eliminated.

  In the ice making machine configured as described above, the outlet temperature sensor 38 for detecting the temperature of the outlet 34a of the evaporator 34 is adopted as the temperature sensor for detecting the temperature of the ice making section 11. However, the present invention is not limited to this. Instead, the temperature at the center of the ice making unit 11 may be detected, or the temperature at the inlet of the evaporator 34 may be detected.

  DESCRIPTION OF SYMBOLS 10 ... Ice maker, 11 ... Ice making part, 13 ... Ice making chamber, 21 ... Ice making water tank, 22 ... Water tray, 25 ... Water pump, 30 ... Refrigerating device, 31 ... Compressor, 32 ... Condenser, 33 ... Electronic expansion Valve, 34 ... Evaporator, 38 ... Temperature sensor (outlet temperature sensor), 39 ... Electronic expansion valve temperature sensor, 40 ... Control device.

Claims (7)

An ice making section having a number of ice making chambers opening downward;
A water dish disposed on the lower side of the ice making unit, and capable of opening and closing a lower opening of the ice making chamber;
An ice making water tank for storing ice making water to be supplied to the ice making chamber;
A water supply pump for injecting and sending ice making water in the ice making water tank from below into the ice making chamber;
A refrigeration apparatus for cooling the ice making unit;
A control device for controlling the operation of the water pump and the refrigeration apparatus,
The refrigeration apparatus includes a compressor that compresses a 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, An evaporator that evaporates the liquefied refrigerant expanded by the electronic expansion valve and cools the ice making unit;
In the ice making operation for 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. Cooling the ice making part with the heat of vaporization of the vaporized liquefied refrigerant in the evaporator,
While the ice making water sprayed and delivered by the water pump into the ice making chamber is cooled in the ice making chamber, unfrozen ice making water is collected in the ice making water tank, and the ice making water is collected in the ice making water tank, the ice making chamber, An ice making machine that produces ice by gradually freezing while circulating between
A temperature sensor for detecting the temperature of the ice making part is provided,
The control device controls the opening degree of the electronic expansion valve based on the temperature detected by the temperature sensor so that the opening degree of the electronic expansion valve is set corresponding to the temperature of the ice making unit. A featured ice machine. The ice maker according to claim 1, wherein the temperature sensor detects a temperature of an outlet of a refrigerant of the evaporator in the ice making unit. The ice making machine according to claim 1 or 2,
The opening degree of the set electronic expansion valve is set to be an opening degree reduction rate according to a temperature drop of the ice making part, and the opening degree reduction rate is three or more steps according to the temperature range of the ice making part. An ice machine characterized by being set to change with. The ice making machine according to claim 3,
The temperature range of the ice making unit includes a temperature range of a cooling stage in which the ice making water sprayed and delivered into the ice making chamber is cooled before freezing in the ice making chamber, and a freezing start in which the ice making water starts to freeze in the ice making chamber An ice making machine comprising: a temperature range in a stage; and a temperature range in an ice growth stage in which ice is grown in the ice making chamber. The ice making machine according to claim 3 or 4,
The control device maintains the opening of the electronic expansion valve without changing when the temperature detected by the temperature sensor rises, and the electronic when the temperature detected by the temperature sensor maintains without changing the opening. An ice making machine characterized in that when the temperature drops again to a temperature corresponding to the opening degree of the expansion valve, the control to resume the opening degree of the electronic expansion valve corresponding to the temperature of the ice making part is resumed. . An ice making section having a number of ice making chambers opening downward;
A water dish disposed on the lower side of the ice making unit, and capable of opening and closing a lower opening of the ice making chamber;
An ice making water tank for storing ice making water to be supplied to the ice making chamber;
A water supply pump for injecting and sending ice-making water in the ice-making water tank from below to the ice-making chamber, and a refrigeration apparatus for cooling the ice-making unit;
A control device for controlling the operation of the water pump and the refrigeration apparatus,
The refrigeration apparatus includes a compressor that compresses a 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, An evaporator that evaporates the liquefied refrigerant expanded by the electronic expansion valve and cools the ice making unit;
In the ice making operation for 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. Cooling the ice making part with the heat of vaporization of the vaporized liquefied refrigerant in the evaporator,
While the ice making water sprayed and delivered by the water pump into the ice making chamber is cooled in the ice making chamber, unfrozen ice making water is collected in the ice making water tank, and the ice making water is collected in the ice making water tank, the ice making chamber, An ice making machine that produces ice by gradually freezing while circulating between
The refrigeration apparatus includes a first connection pipe connecting the condenser and the electronic expansion valve, and a second connection pipe connecting the evaporator and the compressor, and the first connection pipe. A path and the second connection pipe line are arranged in a state in which heat exchange is possible with each other,
An electronic expansion valve temperature sensor for detecting the inlet temperature of the electronic expansion valve is provided,
The ice making machine, wherein the control device controls an opening degree of the electronic expansion valve based on a temperature detected by the electronic expansion valve temperature sensor. The ice making machine according to claim 6,
A temperature sensor for detecting the temperature of the ice making part is provided,
The said control apparatus controlled the opening degree of the said electronic expansion valve based on the detection temperature of the said electronic expansion valve temperature sensor, and the detection temperature of the said temperature sensor, The ice making machine characterized by the above-mentioned.

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