JP2009121768A - Automatic ice making machine and control method for it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic ice making machine and its control method, preventing double ice making. <P>SOLUTION: In the ice making operation, a refrigerant is circulated and supplied to an evaporator 20 to cool an ice making plate 18, thereby making the ice making plate 18 generate ice, and in the deicing operation, the ice making plate 18 is heated to remove the ice generated in the ice making plate 18. This automatic ice making machine includes: a thermistor 24 for detecting the refrigerant temperature in the ice making operation, which is provided on the outlet side of an evaporator 20; and a control means which determines that the ice unremoved by the preceding ice removing operation remains on the ice making plate 18 when the refrigerant temperature in the ice making operation, detected by the thermistor 24 agrees with a preset abnormal temperature. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an automatic ice making machine and a control method therefor, and more particularly, to an automatic ice making machine and a control method therefor that prevent occurrence of double ice making by detecting the occurrence of double ice making in an ice making unit. Is.

  As an automatic ice maker that continuously produces ice, an evaporator derived from a refrigeration system (refrigeration system) is placed on the back of an ice making plate that is erected vertically, and is cooled by a refrigerant that is circulated and supplied to the evaporator. There is known a flow-down type ice making machine in which ice making water is sprayed and supplied to the surface (ice making surface) of the ice making plate to form ice, and the obtained ice is peeled off and released. In this ice making machine, in the ice making operation, the refrigerant is circulated and supplied to the evaporator, and ice making water is sprayed and supplied to the ice making surface of the ice making plate. When the ice making is completed, the circulation supply of the refrigerant and the supply of the ice making water are stopped to complete the ice making operation, and the hot gas circulation supply and the deicing water supply are respectively performed to start the deicing operation.

A deicing detection thermo is arranged on the outlet side of the evaporator, and deicing detection is performed when the temperature of the hot gas rising when the ice is separated from the ice making plate by the deicing operation reaches the deicing completion temperature. When the thermo is detected, the hot gas circulation supply and the deicing water supply are stopped, the deicing operation is terminated, and the ice making operation is started.
Japanese Patent Laid-Open No. 10-170113

  In a conventional flow-down type ice making machine, as described above, the deicing detection thermo detects the deicing completion temperature and shifts from the deicing operation to the ice making operation, but the setting of the detected temperature is determined empirically. Even when the thermo detects the deicing completion temperature, the ice may remain on the ice making surface and may not be completely removed from the ice making plate. When the deicing operation is completed with the ice remaining on the ice making plate and the operation is shifted to the ice making operation, the hot gas circulation supply and the deicing water supply are stopped, and at the same time, the refrigerant and the ice making water are supplied. As a result, larger ice is produced by overlapping the remaining ice as a nucleus. That is, in the conventional flow-down type ice making machine, so-called double ice making is performed in which the produced ice remains without being removed from the ice making surface and is made again. When this double ice making is repeated, there is a problem that deformed ice or larger ice than usual is formed.

  In view of the above-mentioned problems inherent in the above-described conventional technology, the present invention has been proposed to suitably solve this problem, and provides an automatic ice making machine capable of detecting double ice making. For the purpose.

In order to overcome the above-mentioned problems and achieve the intended purpose, an automatic ice maker according to claim 1 of the present application provides:
During the ice making operation, ice making water is supplied to the ice making plate cooled by circulating supply of the refrigerant to the evaporator to generate ice on the ice making plate, and during the ice removing operation, the ice making plate is heated to produce the ice making plate. In an automatic ice maker that removes the ice produced on the plate,
Refrigerant temperature detection means for detecting the refrigerant temperature during ice making operation on the outlet side of the evaporator;
When the refrigerant temperature during the ice making operation detected by the refrigerant temperature detecting means coincides with a preset abnormal temperature, the ice making plate contains ice that could not be removed by the previous deicing operation. And a control means for determining.
According to the first aspect of the present invention, it is possible to reliably detect a state in which ice that could not be removed by the previous deicing operation remains on the ice making plate, and prevent adverse effects due to the state.

The gist of the invention according to claim 2 is that the control means performs control for correcting the abnormal temperature based on a detected value of the outside air temperature detecting means for detecting the outside air temperature.
According to the second aspect of the present invention, it is possible to accurately detect a state in which ice that could not be removed by the previous deicing operation remains on the ice making plate regardless of the outside temperature.

In order to overcome the above-mentioned problems and achieve the intended purpose, an automatic ice maker according to claim 3 of the present application provides:
During ice making operation, each ice making plate facing the ice making surface is cooled by circulating supply of refrigerant to the evaporator, and ice making water is supplied to each ice making plate to generate ice on the ice making plate. In the automatic ice making machine that removes the ice generated on the ice making plate by heating the ice making plate,
A drain pan disposed on the side of the plurality of ice making plates facing each other, and receiving water flowing down the sides of the ice making plate;
In the normal state in which the ice is completely removed from the ice making plate by the previous deicing operation, the drain pan is set to an inner diameter dimension that allows the drain pan to discharge without accumulating a large amount of water. A hose,
Water level detection means for detecting the water level in the drain pan;
When the water level detection means detects that the water level in the drain pan matches a preset abnormal water level, it is determined that ice that could not be removed by the previous deicing operation remains on the ice making plate. And a control means.
According to the invention of claim 3, as in the invention of claim 1, the state in which ice that could not be removed by the previous deicing operation remains on the ice making plate is reliably detected, and this state It can prevent harmful effects caused by

According to a fourth aspect of the present invention, the control means performs a deicing operation performed immediately after it is determined that ice that could not be removed in the previous deicing operation remains, rather than a normal deicing operation. The main point is to perform control for a long time.
According to the invention which concerns on Claim 4, the ice which could not be removed by the previous deicing operation to an ice making board can be removed reliably, and an automatic ice making machine can be recovered to a normal state.

According to a fifth aspect of the present invention, the control means supplies the refrigerant to the evaporator after completion of the deicing operation immediately after it is determined that the ice that could not be removed by the previous deicing operation remains. The gist is to perform control so as to perform a cleaning operation in which ice-making water is circulated and supplied to the ice-making plate.
According to the invention according to claim 5, as in the invention according to claim 4, the ice that could not be removed by the previous deicing operation is reliably removed from the ice making plate, and the automatic ice making machine is restored to the normal state. Can be.

In order to overcome the above-mentioned problems and achieve the intended purpose, the manufacturing method of the automatic ice making machine of the invention according to claim 6 of the present application,
An ice making operation for supplying ice making water to an ice making plate cooled by circulating supply of refrigerant to the evaporator to generate ice on the ice making plate, and heating the ice making plate to remove the ice formed on the ice making plate In the control method of the automatic ice maker that repeats the deicing operation alternately,
When the refrigerant temperature during the ice making operation detected by the refrigerant temperature detecting means disposed on the outlet side of the evaporator matches the preset abnormal temperature, the ice making plate is removed by the previous deicing operation. It is characterized in that it is determined that the unobtained ice remains.
According to the invention of claim 6, it is possible to reliably detect a state in which ice that could not be removed by the previous deicing operation remains on the ice making plate, and to perform control that can prevent adverse effects due to the state. Become.

The gist of the invention according to claim 7 is that an outside air temperature detecting means for detecting the outside air temperature is provided, and the abnormal temperature is corrected based on a detected value of the outside air temperature detecting means.
According to the seventh aspect of the invention, it is possible to accurately detect a state in which ice that could not be removed by the previous deicing operation remains on the ice making plate regardless of the outside temperature.

In the invention according to claim 8, the abnormal temperature is set to a temperature lower than the minimum temperature of the refrigerant flowing through the evaporator in a normal state in which ice is completely removed from the ice making plate in the previous deicing operation. Is the gist.
According to the eighth aspect of the invention, it is possible to accurately detect a state in which ice that could not be removed by the previous deicing operation remains on the ice making plate regardless of the outside temperature.

  According to the automatic ice making machine and the control method thereof according to the present invention, it is possible to detect a state in which ice that could not be removed by the previous deicing operation remains on the ice making plate.

  Next, the automatic ice making machine and the control method thereof according to the present invention will be described below with reference to the accompanying drawings by way of preferred embodiments. In the following description, a state where double ice making has occurred is referred to as an “abnormal state”, and a normal state other than that is referred to as a “normal state”.

  As shown in FIG. 1, the automatic ice making machine 10 of the embodiment is a flow-down type, and an ice making mechanism 14 that generates ice blocks (ice) and an ice storage chamber (not shown) that stores the ice blocks obtained from the ice making mechanism 14. ) And the ice making machine main body 12 provided. The ice making mechanism 14 supplies ice making water to each ice making unit 16 from a plurality of ice making parts 16 arranged in parallel at a predetermined interval and an ice making water tank 34 arranged below the ice making parts 16. A system 30 and a cooling system 40 that circulates and supplies a coolant for forcibly cooling the ice making unit 16 are provided. Each ice making section 16 is composed of two ice making plates 18 and 18 arranged vertically opposite to each other with an evaporator 20 described later. The ice blocks obtained by the ice making mechanism 14 are crushed by an ice crusher 15 disposed obliquely below the ice making unit 16 and discharged into an ice storage chamber.

  In addition, on the front surface of the ice making machine main body 12, where the user's operation and visual recognition are easy, various switches relating to the operation of the automatic ice making machine 10, a display device such as the operating state of the automatic ice making machine 10, and the like An operation display unit (not shown) in which an outside temperature thermistor (outside temperature detecting means) 28 for detecting the outside temperature is arranged is provided. Then, the automatic ice maker 10 is turned on and each set value is input by operating the various switches, and the operating state of the automatic ice maker 10 is displayed to the user by the display device. Further, the outside air temperature thermistor 28 is configured to always detect the outside air temperature in the usage environment of the automatic ice making machine 10. The outside air temperature thermistor 28 is disposed at any part as long as it is sufficiently away from the compressor CM serving as a heat source of the automatic ice making machine 10 and the ice making unit 16 to be cooled and can accurately detect the outside air temperature. Is possible.

  Each ice making section 16 has an evaporator 20 which is led out from the cooling system 40 and meanders in the lateral direction in close contact with the opposite surfaces (back surfaces) of the ice making plates 18, 18. By circulating supply to 20, both ice making plates 18 and 18 are forcibly cooled. On the other hand, the ice making plates 18 and 18 are heated by circulating and supplying hot gas from the cooling system 40 to the evaporator 20 during the deicing operation. Further, a slope 22 configured to guide the obtained ice block to the ice storage chamber and to separate the ice block and water is disposed immediately below the ice making unit 16. That is, the ice making water supplied to the ice making surfaces (front surfaces) of the ice making plates 18 and 18 during the ice making operation and the deicing water supplied to the back surfaces of the ice making plates 18 and 18 during the deicing operation are downward via the slope 22. It is collected and stored in the ice making water tank 34 located at the position.

  The ice making water supply system 30 includes an ice making water tank 34 disposed below the plurality of ice making units 16, an ice making water sprinkling header 36 disposed above each ice making unit 16, an ice making water tank 34, and ice making water sprinkling. An ice making water pipe 38 connecting the header 36 and an ice making water pump 32 inserted in the ice making water pipe 38 are provided, and the ice making water is circulated and supplied during ice making operation. The ice making water sprinkling header 36 is provided with a large number of water sprinkling holes (not shown), and ice making water pumped by the ice making water pump 32 from the ice making water tank 34 during ice making operation is supplied from the water sprinkling holes to the ice making plate 18. , 18 is sprayed on the ice making surface cooled to the freezing temperature to generate a plate-shaped ice block having a required thickness on the ice making surface.

  Further, by switching the hot gas valve HV disposed in the cooling system 40, hot gas is circulated and supplied to the evaporator 20 to heat the ice making plates 18 and 18, and the ice formation surface between each ice making surface and ice blocks is formed. In the deicing operation for melting, a deicing water supply system 51 is provided separately from the ice making water supply system 30 to spread deicing water on the back surfaces of the ice making plates 18 and 18 and to promote deicing by raising the temperature. Yes. The deicing water supply system 51 includes a deicing water tank 54 disposed in the vicinity of the compressor CM, a deicing water sprayer 56 provided at the upper back of each ice making unit 16, a deicing water tank 54, and a deicing water sprayer. 56, a deicing water pipe 57 connected to the deicing water pipe 57, and a deicing water supply pipe 58 connected to an external water source via a water supply valve WV. The deicing water supplied to and stored in the ice water tank 54 from an external water source is supplied to the back surface of the ice making unit 16 during the deicing operation (see FIG. 1). Then, by operating the deicing water pump 52 during the deicing operation, the deicing water stored in the deicing water tank 54 is sprayed and supplied from the deicing water sprayer 56 to the back side of the ice making plate 18 and flows down. It is designed to melt ice surfaces with ice blocks. The deiced water flowing down the back side of the ice making plate 18 is collected in the ice making water tank 34 through the slope 22 in the same manner as the ice making water, and this is used as the next ice making water. Moreover, the solid line arrow in FIG. 1 has shown the flow of the refrigerant | coolant in the cooling system 40, and the broken line arrow has shown the flow which concerns on the circulation of deicing water.

A first circulation pipe 62 communicating with the tank 54 and a second circulation pipe 64 opening above the tank 54 are connected to the deicing water tank 54 via a circulation pump 66. That is, one end of the first circulation pipe 62 is connected to the lower surface of the deicing water tank 54 and the other end is connected to the suction side of the circulation pump 66. The second circulation pipe 64 has one end connected to the discharge side of the circulation pump 66 and the other end connected to discharge deiced water used for circulation from above the deicing water tank 54 ( (See FIG. 1). Then, by starting the circulation pump 66, the deicing water stored in the deicing water tank 54 is sucked through the first circulation pipe 62 and discharged to the deicing water tank 54 through the second circulation pipe 64. Thus, the deicing water in the deicing water tank 54 is circulated (stirred). A deicing water thermostat 68 serving as a deicing water temperature detecting means for detecting the temperature of the deicing water is disposed below the surface of the deicing water stored in the deicing water tank 54. The discharge port of the second circulation pipe 64 is set so as to face the discharge pipe 46 (described later), and the deicing water in circulation discharged from the discharge port hits the discharge pipe 46 (FIG. 1). reference).

  The ice making water tank 34 is provided with a tank float switch TS as ice making water tank water level detecting means connected to the control means C shown in FIG. 2, and setting of ice making water stored in the tank 34 by the switch TS. The water level (storage amount) is detected. Further, the ice making water tank 34 is provided with a drainage pump 33 for discharging ice making water stored therein to the outside of the tank 34 as necessary.

  The cooling system 40 includes a compressor CM, a condenser 42 (fan motor FM), an electromagnetic valve 44, an expansion valve (not shown), and an evaporator 20 in this order, a discharge pipe (refrigerant pipe) 46, and a suction pipe ( The refrigerant pipe 48 is connected (see FIG. 1). The electromagnetic valve 44 is controlled by the control means C so as to be opened during the ice making operation and closed during the deicing operation. In the ice making operation, the refrigerant compressed by the compressor CM is condensed and liquefied by the condenser 42 via the discharge pipe 46, and is decompressed by the expansion valve via the electromagnetic valve 44 that controls circulation supply of the refrigerant. The ice making plate 18 expands and evaporates all at once, and performs heat exchange with the ice making plate 18 to cool the ice making plate 18 to below the freezing point. The refrigerant evaporated in the evaporator 20 returns to the compressor CM through the suction pipe 48 and is supplied to the condenser 42 again. The expansion valve is provided at a required position in the evaporator 20 and includes a temperature sensing cylinder for detecting the temperature of the refrigerant flowing through the evaporator 20, and the refrigerant detected by the temperature sensing cylinder. The opening degree of the valve is automatically controlled according to the temperature. Specifically, when the temperature of the ice making plate 18 is low and the cooling load is small, the opening degree decreases so as to decrease the flow rate of the refrigerant, and when the temperature of the ice making plate 18 is high and the cooling load is large, the flow rate of the refrigerant is increased. The opening becomes larger so that Further, a portion of the discharge pipe 46 located directly below the second circulation pipe 64 is formed in a spiral shape, and when the deicing water discharged from the discharge port of the second circulation pipe 64 comes into contact with the discharge pipe 46, The refrigerant and the deicing water that circulates are configured to efficiently exchange heat.

  The cooling system 40 includes a hot gas pipe 50 branched from the compressor CM. The hot gas pipe 50 passes through the hot gas valve HV, and then merges with the discharge pipe 46 and communicates with the inlet side of the evaporator 20. Yes. The hot gas valve HV is controlled by the control means C so as to be closed during the ice making operation and to be opened during the deicing operation. In the deicing operation, the hot gas discharged from the compressor CM is bypassed to the evaporator 20 via the opened hot gas valve HV and the hot gas pipe 50, and the ice making plate 18 is heated, thereby producing the ice making surface. The icing surface of the ice mass generated in the above is melted, and the ice mass is dropped by its own weight. That is, by operating the compressor CM and opening / closing the solenoid valve 44 and the hot gas valve HV, the ice making operation and the deicing operation are alternately repeated to produce ice blocks. .

  On the refrigerant outlet side of the evaporator 20, a thermistor 24 as refrigerant temperature detecting means for detecting the temperature of the refrigerant (heater outlet temperature) after heat exchange with the ice making plate 18, and the pressure of the refrigerant are detected. A pressure sensor 26 is provided as a refrigerant pressure detecting means. Specifically, the suction pipe 48 connected to the outlet side of the evaporator 20 is disposed in the vicinity of the outlet of the evaporator 20. The detected temperature of the thermistor 24 and the detected pressure of the pressure sensor 26 are input to the control means C.

  The automatic ice making machine 10 includes a control unit C that supervises the overall electrical control. As the control unit C, a programmable controller including an MPU is used. As shown in FIG. 2, the control means C includes a compressor CM, a fan motor FM, an electromagnetic valve 44, a hot gas valve HV, a water supply valve WV, an ice making water pump 32, a drainage pump 33, a deicing water pump 52, and a circulation pump 66. The tank float switch TS, the thermistor 24, the pressure sensor 26, the outside temperature thermistor 28, the deicing water thermostat 68, various switches and a display device are connected. Under the control of the control means C based on these components, the pump 32, 33, the cooling system 40, and the like perform a predetermined operation. Further, the control means C includes a storage unit M capable of storing each setting value necessary for ice making operation and deicing operation, and switching of the operation.

After the thermistor 24 detects a preset deicing completion temperature (for example, 4 ° C.), the control means C counts the deicing completion delay time for completing the deicing completion in the normal state. It comprises use timer DT _N (see FIG. 2). In addition, wherein the control unit C, "abnormal condition" during circulation and supply time abnormal state during deicing timer DT A _(described later) for measuring the hot gas is also provided. The abnormal state during deicing timer DT _A are counted to "normal state" temperature detection + normal state during deicing timer DT _N The time required from the strictly longer time by the thermistor 24 in (for example, 2 minutes) It is comprised so that it may do. The normal state during deicing timer DT _N, upon the deicing operation, so that the thermistor 24 starts counting from the time of detecting the deicing completion temperature, to stop the preset deicing completion delay time after counting Is set. Incidentally, the timer DT _N for at deicing normal state, counting is reset when the stop. Moreover, since the said control means C is comprised from a programmable controller, each numerical value mentioned above can be changed freely.

  After the ice making operation is started, the control means C stops the ice making operation when the tank float switch TS detects that the water level in the ice making water tank 34 has dropped to the specified water level and has reached the specified water level. Then, control to switch to deicing operation is performed. Further, the control means C detects the temperature of the hot gas that rapidly rises by removing the ice block from the ice making plate 18 after the start of the deicing operation, and the temperature of the hot gas is preset. It is set to detect that the deicing completion temperature has been reached, and to determine that deicing has been completed after elapse of a preset deicing completion delay time, and to switch the deicing operation to the ice making operation. . Further, after the ice making operation is started, the control means C, when the thermistor 24 detects that the temperature of the refrigerant has decreased / matched to a preset double ice making detection temperature (abnormal temperature), It is determined that the ice block has not been removed from the ice making plate 18 and the ice making plate 18 has double ice making, and the operation of the automatic ice making machine 10 is stopped. It is designed to display the user. The double ice making detection temperature is a temperature lower than the lowest temperature at which the refrigerant flowing through the evaporator 20 falls most in the “normal state”, and double ice making occurs on the ice making plate 18 and the ice removal operation is completed. This temperature is detected when ice blocks remain on the ice making plate 18. For example, the refrigerant temperature decreasing to −25 ° C. in the “normal state” is lower than −30 ° C. in the “abnormal state”.

  Further, the double ice making detection temperature fluctuates by being influenced by the outside air temperature. For example, the double ice making detection temperature rises in summer and falls in winter, so that it is corrected and set to a different value depending on the outside air temperature detected by the outside air temperature thermistor 28. It has become. For example, when the outside air temperature detected by the outside air temperature thermistor 28 exceeds 20 ° C., the double ice making detection temperature is set to −25 ° C., and when the outside air temperature is 20 ° C. or below, the double ice making is performed. The detected temperature is set to −30 ° C.

(Operation of Example)
Next, the operation of the automatic ice making machine and its control method according to the embodiment will be described below. The ice making water tank 34 stores enough ice making water to generate the necessary ice blocks in the ice making unit 16, while the deicing water tank 54 stores the next ice making water and the automatic ice making machine. It is assumed that various set values for normal operation are input to the storage unit M. Then, based on information (signals) from the thermistor 24, pressure sensor 26, tank float switch TS, various switches, and outside temperature thermistor 28, the control means C provides each component such as the ice making water supply system 30 and the cooling system 40. By controlling the operation of the automatic ice maker 10, the automatic ice making machine 10 is operated.

  When the ice making operation is started, the coolant is circulated and supplied from the cooling system 40 to the evaporator 20 of each ice making unit 16 to cool both ice making plates 18 and 18, and the ice making water pump 32 is driven to produce an ice making water tank. The ice making water stored in 34 is supplied to the ice making water sprinkling header 36 through the ice making water pipe 38. The ice making water sprayed and supplied to each ice making unit 16 through the water sprinkling holes of the ice making water sprinkling header 36 is gradually cooled by heat exchange with the ice making plate 18 in the process of flowing down the ice making surface of each ice making plate 18 and partly. Freezes on the ice making surface. Uniced water is collected in an ice making water tank 34 disposed below the ice making unit 16, and the ice making water stored in the ice making water tank 34 is gradually cooled. Then, the ice making water collected in the ice making water tank 34 is supplied again to each ice making unit 16 by the ice making water pump 32, and the amount of ice making water in the ice making water tank 34 gradually decreases with the generation of ice blocks on the ice making surface. .

  When a complete ice block is generated on each of the ice making plates 18, the ice-making water in the ice-making water tank 34 decreases by the amount of ice block generation. The decrease in the ice making water in the ice making water tank 34 is detected by the tank float switch TS, so that it is determined that an ice block having a sufficient thickness has been generated and the operation of the compressor CM is continued. Pump down operation for closing 44 is performed. Then, by the pump-down operation, the refrigerant circulatingly supplied in the cooling system 40 is recovered, and the refrigerant pressure in the suction pipe 48 from the electromagnetic valve 44 to the compressor CM is reduced in the cooling system 40. When the pressure sensor 26 detects that the refrigerant pressure has become a certain value (for example, 0.05 MPa) or less, the ice making water pump 32 is stopped and the ice making water in the ice making water supply system 30 is stopped. And the hot gas valve HV is controlled to be opened. Note that the decrease in the refrigerant pressure reaches a minimum immediately before completion of the pump-down operation and reaches a minimum value. Further, the drain pump 33 is turned on, and the ice making water remaining in the ice making water tank 34 and not used for ice making is discharged outside the automatic ice making machine 10. Due to the discharge of the remaining ice-making water, the ice-making water that is concentrated in a non-volatile substance such as calcium salt due to the evaporation of the ice-making water due to the operation of the automatic ice making machine 10 is used as the next ice-making water. It is possible to avoid the inconvenience of using it.

  When the hot gas valve HV is opened, hot gas is circulated and supplied to the evaporator 20, and deiced water pumped by the deicing water pump 52 is sprayed and supplied to the back side of the ice making plate 18 via the deicing water sprayer 56. It flows down to melt the icing surface of the ice making plate 18 and the ice block. In this way, hot gas is circulated and supplied with deicing water, so that the ice formation surface of each ice making plate 18 and ice blocks is melted, and the ice blocks removed from each ice making plate 18 are released into the ice storage chamber. Stored. At this time, the temperature of the deicing water is detected by the thermostat 68 for deicing water, and when the temperature falls below a certain temperature, the circulation pump 66 is operated to cause heat exchange by bringing the deicing water into contact with the discharge pipe 46. It is designed to maintain a temperature above a certain level. For this reason, the icing surface of the ice making plate 18 is suitably melted by using deicing water. Then, the deicing water flows into the ice making water tank 34 and begins to be stored as ice making water used for the next ice making operation. The ice crusher 15 continues to rotate at a constant speed during the deicing operation. Further, the refrigerant temperature detected by the thermistor 24 becomes the lowest when the refrigerant pressure becomes the lowest, for example, about -25 ° C. during the winter season when the ambient temperature of the automatic ice making machine 10 is low.

When the ice blocks are removed from each ice making plate 18, the heat of the hot gas circulated and supplied to the evaporator 20 is not used for melting the frozen surface, so the temperature of the hot gas coming out of the evaporator 20 is Start climbing. When the thermistor 24 detects that the temperature of the hot gas has reached the deicing completion temperature, it is determined that the ice block has been removed from each ice making plate 18. Then, in order to reliably achieve the removal from the ice making plate 18 of the ice mass, after which the thermistor 24 detects a temperature rise, a further deicing operation waits for the time-out of the normal state during deicing timer DT _N finish. That is, the hot gas valve HV is controlled to be closed, and the hot gas circulation supply is stopped. Then, the operation shifts to the ice making operation. At the same time, the electromagnetic valve 44 is controlled to be opened, the refrigerant is circulated and supplied to the evaporator 20, and the ice making water pump 32 is operated to supply ice making water to the ice making plate 18. At the same time as the ice making operation is started, the water supply valve WV is controlled to be opened, and deicing water used in the next deicing operation is supplied into the deicing water tank 54 in a predetermined amount.

  By shifting to the ice making operation, the refrigerant circulated and supplied to the evaporator 20 first absorbs heat accumulated by the hot gas circulation supply in the above-described deicing operation in the “normal state”. In the vicinity of the outlet of the evaporator 20 where is disposed, the temperature becomes high. When the temperature sensing cylinder that performs the automatic opening degree control of the expansion valve detects this high temperature, the opening degree of the expansion valve is increased in accordance with the temperature of the refrigerant flowing through the evaporator 20 and flows through the evaporator 20. The amount of refrigerant to be increased increases. Therefore, the heat exchanging capacity for taking away the heat of the ice making plate 18 is increased.

Ice cubes contrast, in "abnormal condition", led to the refrigerant temperature deicing completion temperature flowing through the evaporator 20, the ice making plate 18 further even after normal state during counting of the deicing timer DT _N is completed Remains frozen. Accordingly, since the ice remains on the ice making plate 18, the heat exchange efficiency in the evaporator 20 is deteriorated, the refrigerant is difficult to evaporate, the expansion valve is closed, the internal pressure is lowered, and the temperature is lowered. This decrease in the refrigerant temperature is lower than the lowest refrigerant temperature (−25 ° C. during the winter period) during the pump-down operation described above, and reaches −30 ° C. during the winter period. That is, the refrigerant temperature is lowered to a temperature that cannot be considered in the “normal state”. In this embodiment, a temperature that cannot be considered in this “normal state” (−30 ° C. during the winter period) is set as a double ice-making detection temperature, and when the thermistor 24 detects this temperature, It is determined that the control means C is in an “abnormal state” in which double ice making has occurred.

  Then, when the thermistor 24 detects the double ice making detection temperature and the control means C determines “abnormal state”, the compressor CM and the ice making water pump 32 are stopped and controlled immediately to prevent double ice making. The ice making operation will be stopped. That is, since the double ice making does not proceed, various adverse effects related to the double ice making can be prevented, and the double ice making can be reliably detected at the initial stage. Recovery to can be easily achieved in a short time. On the other hand, when the thermistor 24 does not detect the “abnormal state” and is determined to be “normal state”, the ice making operation is continued, and thereafter, the ice making operation and the removal are continued until the ice block is sufficiently stored in the ice storage chamber. The ice operation is repeated alternately.

  A case where the “abnormal state” is determined by the detection of the thermistor 24 will be described with reference to FIG. 3. A routine of “normal state” in which “ice-making operation”-“deicing operation” is repeated becomes “abnormal state”. Control flow proceeds to the control routine Ra. Specifically, the ice making operation is stopped (step S1), and the operation is immediately shifted to the deicing operation (step S2). Thus, by immediately shifting from the ice making operation to the deicing operation, it is possible to minimize the adverse effects of double ice making. Further, the ice crusher 15 which starts the operation and shifts to the deicing operation at the “normal operation” is controlled not to operate at all at the “abnormal state”. By controlling the ice crusher 15 in this way, it is possible to prevent the ice crusher 15 from being damaged by crushing of abnormally grown ice blocks that may be released from the ice making unit 16 in the deicing operation in the “abnormal state”. .

When shifting to the “deicing operation”, hot gas is circulated and supplied to the evaporator 20, and deicing water starts to be supplied to the ice making unit 16. The completion timing of the deicing operation in the “normal state” is that the refrigerant flowing through the suction pipe 48 detected by the thermistor 24 has reached the deicing completion temperature and the deicing in the normal state after detecting the temperature. It had been determined by the use a timer DT _N, in "abnormal state" is controlled only by the timer count using an abnormal state during deicing timer DT _a. That is, the abnormal state during deicing timer DT _A starts counting of the predetermined time (step S3). And, the time for the counting abnormal state during deicing timer DT _A is a longer predetermined time from the count time required by the temperature detection by the thermistor 24 in the "normal state" + normal state during deicing timer DT _N Set to time (eg 2 minutes). As described above, since the deicing is controlled only by counting the time without using the temperature of the refrigerant flowing through the suction pipe 48, the ice blocks that could not be deiced from the ice making plate 18 can be reliably removed.

When the count is completed by the timer DT _A for abnormal conditions during deicing at step S3, to stop the operation of the automatic ice-making machine 10 (step S4). Then, along with the operation stop of the automatic ice maker 10, the user is made aware via the display device that the operation of the automatic ice maker 10 has been stopped due to the occurrence of an “abnormal state”. . By making the user aware of the stop of the automatic ice making machine 10 due to this “abnormal state”, the user can clearly recognize that it is different from the normal device stop (step S5), and the automatic ice making is performed according to the “abnormal state”. Various adverse effects expected to occur in the machine 10 can be confirmed in advance when the automatic ice making machine 10 is restarted.

  As described above, according to the automatic ice making machine and the control method thereof according to the present embodiment, the removal of the ice block from the ice making plate 18 is detected, and the information (signal) for controlling the transition from the ice making operation to the deicing operation is output. Therefore, since the “abnormal state” related to double ice making is detected using the thermistor 24 already incorporated in the automatic ice making machine 10, there is no need to newly install a dedicated member or the like. That is, the manufacturing cost does not increase compared to the conventional product. The details of the ice making operation and the deicing operation in the “normal state” in FIG. 3 are omitted.

(Another example)
In the foregoing embodiment, the thermistor 24 detects the “abnormal state” from the refrigerant temperature after the transition from the deicing operation to the ice making operation, but the present invention is not limited to this. For example, the automatic ice making machine 70 shown in FIG. 4 has basically the same structure as the automatic ice making machine 10 according to the embodiment, and further, drain pans 72 and 72 are disposed below both sides of each ice making plate 18. A drain hose 74 for discharging water received by the drain pan 72 out of the automatic ice making machine 70 is provided at the bottom of each drain pan 72. Specifically, as shown in FIG. 5, the plurality of ice making plates 18, 18 constituting each ice making unit 16 are arranged at a predetermined interval so as to face the ice making surfaces (FIG. 5A). reference). In such a configuration, double ice making occurs on each of the opposing ice making plates, and the ice blocks are connected and closed (see FIG. 5B). Then, ice making water that cannot enter between the ice making plates 18 and 18 reaches both sides of the ice making plates 18 and 18. That is, each drain pan 72 is disposed at a site where ice making water that cannot enter between the ice making plates 18 and 18 flows down to both sides of the ice making plates 18 and 18.

  That is, the ice making water supplied to the ice making plate 18 flows into the drain pan 72 when an “abnormal state” in which double ice making occurs. Each drain pan 72 is configured such that in the “normal state”, dew condensation water generated on the ice making plate 18 during the ice making operation and defrost water generated near the entrance / exit of the evaporator 20 during the deicing operation flow. ing. In FIG. 4, the solid line arrow indicates the flow path of the ice making water in the “abnormal state”, and the double-dotted line arrow indicates the flow path of the ice making water in the “normal state”.

  Each drain pan 72 is provided with a float switch (water level detecting means) FS for detecting the abnormal water level when the water level rises and coincides with the abnormal water level due to the ice-making water that flows in and accumulates under the “abnormal condition”. It has been. If the float switch FS does not detect an abnormal water level, the control means C determines that the automatic ice making machine 70 is “normal state”, and if it detects an abnormal water level, it determines “abnormal state”. The control means C that controls the overall electrical control of the automatic ice making machine 70 is basically the same as the control means C of the automatic ice making machine 10 shown in FIG. 2, and a float switch FS is added. The point is different. That is, the control means C related to the automatic ice making machine 70 includes a compressor CM, a fan motor FM, a solenoid valve 44, a hot gas valve HV, a water supply valve WV, an ice making water pump 32, a drainage pump 33, as shown in FIG. A deicing water pump 52, a circulation pump 66, a tank float switch TS, a float switch FS, a thermistor 24, a pressure sensor 26, an outside air temperature thermistor 28, a deicing water thermostat 68, various switches and a display device are connected to these components. Under the control of the control means C based on this, devices such as the pumps 32 and 33 and the cooling system 40 perform a predetermined operation.

  As shown in FIG. 7, the drain hose 74 is set such that when the automatic ice making machine 70 is in a “normal state”, the drain pan 72 can discharge without accumulating a large amount of water (see FIG. 7). 7 (a)). Specifically, the amount of condensed water generated in the ice making plate 18 and received by the drain pan 72 in the “normal state” and the amount of defrost water generated near the inlet / outlet of the evaporator 20 and flowing into the drain pan 72 are allowed. As the amount of drainage, the inner diameter dimension is set so as to achieve discharge of the allowable amount of drainage. That is, all the water received by the drain pan 72 in the “normal state” is quickly discharged to the outside through the drain hose 74, so that the water level in the drain pan 72 does not rise. On the other hand, when double ice making occurs in the automatic ice making machine 70 and an “abnormal state” occurs, water exceeding the amount that the drain hose 74 can discharge flows into the drain pan 72.

  Therefore, in the “abnormal state”, the float switch FS detects that the water level in the drain pan 72 gradually rises and the water level rises to the abnormal water level (see FIG. 7B). When the detection operation of the float switch FS continues for a certain time (for example, 2 seconds), the ice making water pump 32 is stopped and the operation of the cooling system 40 of the automatic ice making machine 70 is also stopped. As a result, it is possible to avoid a situation in which the “abnormal state” continues and double ice making progresses, the ice making unit 16 and the ice crusher 15 are damaged due to the occurrence of double ice making, and water flows into the ice storage chamber. . As in the above-described embodiment, the user is made aware through the display device that the operation of the automatic ice maker 70 has been stopped due to the occurrence of an “abnormal condition”, which is different from a normal equipment stoppage. The user is clearly recognized.

(Example of change)
(1) In the above embodiment, double ice by detecting when it is judged "abnormal condition", using the abnormal state deicing timer DT _A, by the thermistor 24 in the "normal state" temperature detection + It had to perform the de-icing of a predetermined time longer than the count the time required by the normal state during deicing timer DT _N, the present invention is not limited thereto. For example, after completion of the deicing operation in the “normal state”, water is further supplied to the ice making water tank 34, and then the ice making water pump 32 is operated while the compressor CM is stopped, thereby the ice making water tank. The control means C may control the “cleaning operation” to supply the water stored in the ice plate 18 to the ice making plate 18. Even if it is a case where the ice lump remaining from the ice making plate 18 without being deiced is very large due to the execution of the “cleaning operation” and cannot be removed even by the deicing operation performed in the “abnormal state” described above, The ice block can be reliably removed. Note that the “cleaning operation” described here is the same as the “ice-making operation” performed with the cooling system 40 stopped, so that the reprogramming of the programmable controller constituting the control means C is very easy, Moreover, since it is not necessary to add a new configuration to the automatic ice maker, there is an advantage that it can be implemented at a low cost.

(2) In the above-described embodiment, the refrigerant temperature at the start of the ice making operation detected by the thermistor 24 is controlled to be changed depending on whether the outside air temperature exceeds 20 ° C or below 20 ° C. The invention is not limited to this. For example, the temperature between the outside air temperature and the temperature detected by the thermistor 24 may be functionalized to set the temperature at which the “abnormal state” is detected by the outside air temperature, and the automatic ice maker may be controlled by these temperatures. . In this case, the detection accuracy of the “abnormal state” becomes accurate.
(3) In the above-described embodiment and modification example (2), the temperature at which the “abnormal state” is detected is automatically corrected and set by the outside air temperature detected by the outside air temperature thermistor 28. The present invention is not limited to this. For example, considering the use of an automatic ice maker in an area where the outside air temperature does not change much throughout the year, the temperature at which the “abnormal state” is detected may be manually corrected and set. In this case, the manufacturing cost of the automatic ice maker can be reduced.
(4) In the above-described embodiment or another embodiment, the thermistor is used as the refrigerant temperature detecting means and the outside air temperature detecting means, and the float switch is used as the ice-making water tank water level detecting means or the drain pan water level detecting means. However, the present invention is not limited to this. As the temperature detection means, the temperature may be detected by a plurality of thermostats, for example, and as the water level detection means, the water level may be detected by, for example, a non-contact type water level sensor.
(5) In the above-described embodiment, a so-called flow-down type automatic ice making machine is taken as an example. However, the present invention is not limited to this. For example, a closed cell type or an open cell type sealed ice making mechanism. An automatic ice maker equipped with other ice making mechanisms may be employed.

1 is a schematic view showing an automatic ice making machine according to a preferred embodiment of the present invention. It is a block diagram which shows a part of control means which controls the automatic ice making machine based on an Example. It is a flowchart which shows the control at the time of the "abnormal state" concerning an Example. It is the schematic which shows the automatic ice making machine which concerns on another Example. It is explanatory drawing which shows the flow of ice-making water when the space between several ice-making boards concerning another Example is obstruct | occluded with an ice lump. It is a part of block diagram of the control means which controls the automatic ice making machine which concerns on another Example. It is explanatory drawing which shows the drain pan float switch in the normal state and abnormal state of the drain pan which concern on another Example.

Explanation of symbols

18 ice making plate, 20 evaporator, 34 ice making water tank, 32 ice making water pump 48 suction pipe, 24 thermistor (refrigerant temperature detecting means),
28 Outside temperature thermistor (outside temperature detection means), 72 drain pan, 74 drain hose CM compressor, FS float switch (water level detection means)

Claims (8)

In the ice making operation, ice making water is supplied to the ice making plate (18) cooled by circulating supply of the refrigerant to the evaporator (20) to generate ice in the ice making plate (18). In an automatic ice making machine that heats the ice making plate (18) to remove the ice formed on the ice making plate (18),
Refrigerant temperature detection means (24) for detecting the refrigerant temperature during the ice making operation on the outlet side of the evaporator (20),
When the refrigerant temperature during the ice making operation detected by the refrigerant temperature detecting means (24) matches a preset abnormal temperature, the ice making plate (18) cannot be removed by the previous deicing operation. And an automatic ice making machine, characterized by comprising control means (C) for determining that there is residual.   The automatic ice maker according to claim 1, wherein the control means (C) performs control for correcting the abnormal temperature based on a detected value of an outside air temperature detecting means (28) for detecting outside air temperature. During ice making operation, each ice making plate (18) facing the ice making surface is cooled by circulating supply of refrigerant to the evaporator (20), and ice making water is supplied to each ice making plate (18) to supply the ice making plate. (18) to generate ice, in the deicing operation, in the automatic ice maker that warms the ice making plate (18) and removes the ice produced on the ice making plate (18),
A drain pan (72, 72) disposed on the side of the plurality of ice making plates (18, 18) facing each other and receiving water flowing down the sides of the ice making plate (18, 18),
In the normal state where the ice is completely removed from the ice making plate (18) by the previous deicing operation, the drain pan (72, 72) has a large amount of water received by the drain pan (72, 72). Drain hose (74,74) set to an inner diameter that can be discharged without accumulating in
Water level detection means (FS) for detecting the water level in the drain pan (72, 72),
When the water level detection means (FS) detects that the water level in the drain pan (72, 72) matches a preset abnormal water level, the ice making plate (18) can be removed by the previous deicing operation. An automatic ice making machine, comprising: control means (C) for determining that no ice has remained.   The control means (C) performs the deicing operation performed immediately after it is determined that ice that could not be removed in the previous deicing operation remains, for a longer time than the normal deicing operation. The automatic ice maker as described in any one of Claims 1-3 which performs control.   The control means (C) stops the supply of refrigerant to the evaporator (20) after the completion of the deicing operation immediately after it is determined that the ice that could not be removed by the previous deicing operation remains. The automatic ice making machine according to any one of claims 1 to 4, wherein the ice making water is controlled to be circulated and supplied to the ice making plate (18). An ice making operation for supplying ice making water to the ice making plate (18) cooled by circulating supply of refrigerant to the evaporator (20) to generate ice on the ice making plate (18), and heating the ice making plate (18) Then, in the control method of the automatic ice maker that alternately repeats the deicing operation for removing the ice generated on the ice making plate (18),
When the refrigerant temperature during the ice making operation detected by the refrigerant temperature detecting means (24) disposed on the outlet side of the evaporator (20) matches a preset abnormal temperature, the ice making plate (18) A method for controlling an automatic ice making machine, characterized in that it is determined that ice that could not be removed in the previous deicing operation remains.   The method for controlling an automatic ice maker according to claim 6, further comprising an outside air temperature detecting means (28) for detecting an outside air temperature, wherein the abnormal temperature is corrected based on a detected value of the outside air temperature detecting means (28).   The abnormal temperature is set to a temperature lower than a minimum temperature of a refrigerant flowing through the evaporator (20) in a normal state in which ice is completely removed from the ice making plate (18) in the previous deicing operation. Or the control method of the automatic ice maker of 7.

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