JP2002310544A - Ice maker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system for preventing production of incomplete ice in an ice maker in which production of cotton ice is prevented by increasing the r.p.m. of a compressor in a refrigeration circuit and lowering the evaporation temperature thereby accelerating creation of nuclei of ice. SOLUTION: In an ice maker for making ice by passing refrigerant from a refrigerant compressor in a refrigeration circuit through an evaporator 15, the refrigerant compressor is formed of an inverter compressor 21 having a variable r.p.m.. The ice maker comprises a water temperature detector 8 for detecting the temperature of ice making water provided in the passage of ice making water, and a cooling performance control means 22 for controlling the r.p.m. of the inverter compressor 21 by an output signal from the water temperature detector 8 wherein the cooling performance control means 22 increases the r.p.m. of the inverter compressor 21 when the water temperature detector 8 detects water temperature higher than and close to 0 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to incomplete ice (hereinafter referred to as "cotton ice") in an ice making machine without deterioration of ice quality.
The present invention relates to an ice maker that prevents the occurrence of ice.

[0002]

2. Description of the Related Art Conventionally, for example, in a water circulation type ice maker, water is flowed on the surface of an ice making plate, and by repeating the process, pure ice without impurities contained on the plate is generated, but the running water is frozen. For this reason, the freezing point was always lower than 0 ° C., and cotton ice was generated just before freezing started. When this type of cotton ice occurs, the ice making water pump is clogged and water flow in the pipeline is deterred, the circulating water is insufficient, and the ice itself becomes cloudy. Since the water is melted with the passage of time, the water circulation by the pump is restored, but if the time required up to that time is long, the temperature of the evaporator becomes too low, and various problems such as completion of ice making due to erroneous detection occur. Therefore, the conventional problem has been solved by the following method. That is, (1) the water passage including the pump is designed so as not to be clogged with cotton ice,
(2) A means for forcibly melting the cotton ice when it is generated, or (3) If the temperature of the evaporator drops to around 0 ° C., then for a certain period of time, even if the temperature drops suddenly and suddenly, ice is made. In order to control the means for canceling the detection of the completion, and (4) to supercool the ice means that ice nuclei cannot be formed. Can be achieved by creating a large temperature difference between
Immediately before reaching ℃, the pump was forcibly stopped for a short time to lower the temperature of the evaporator, and the operation of the pump was returned from this state to form ice crystal nuclei.

[0003] However, the solutions described in the above (1) to (4) are either to avoid inconvenience as an ice maker after the generation of cotton ice, or to actively remove ice crystal nuclei. It can be divided into two patterns, that is, to create them. However, these countermeasures have the following problems. That is, in the above (1), a problem is caused when an amount of cotton ice is generated more than expected.
In the above (2), since the cotton ice is forcibly melted, it acts in a direction opposite to cooling, which is not preferable. In the above (3) and (4), although the time is short, the temperature drops in a state where water is not supplied to the ice making machine (evaporator), so that the heat exchange surface of the ice making machine has a white film layer like frost. As a result, white stripes are formed in the ice, resulting in deterioration of ice quality. As described above, none of the methods is a satisfactory method, and it has been difficult to realize an optimum apparatus for preventing the generation of cotton ice.

Accordingly, the present applicant has previously proposed the invention disclosed in Japanese Patent Publication No. 6-21753 as shown in FIGS. To explain the proposed invention, FIG. 3 shows a water circulation type ice making machine, which includes an ice making water tank 1, a deicing water tank 2, pumps 3 and 4, sprinkling pipes 5, 6, and a refrigeration system including an evaporator 15 (evaporator). The refrigeration circuit includes a compressor 11, a condenser 12, a solenoid valve for refrigerant 18, a heat exchanger 13, an expansion valve 14, and an evaporator 15, an accumulator 16, and a solenoid valve 17 for hot gas, as is known. It is formed by a deicing circuit consisting of: Reference numeral 19 denotes a pressure switch provided in a low-pressure section of the refrigeration circuit, reference numeral 20 denotes a temperature detector attached to the inlet of the evaporator 15 for detecting the saturation temperature of the refrigerant, and reference numeral 8 denotes an ice making water temperature detector for detecting the temperature of ice making water. .

The operation of the proposed invention is as shown in FIG. That is, the deicing cycle is first started when the water level in the ice making water tank 1 has dropped to a certain level. When the pump 4 is started, the deicing water enters the water sprinkling pipe 6 from the deicing water tank 2 via a pipe, and is sprayed from the water sprinkling hole to the back of the ice making plate composed of the evaporator 15 to flow down. Enter the ice making water tank 1 via the route. At the same time, the hot gas solenoid valve 17 of the deicing water circuit is opened to supply hot gas to the evaporator 15 to release the ice adhering to the surface of the ice making water plate. Then, the ice making water tank 1 is filled with deicing water.

Next, the ice making cycle is started after a lapse of a predetermined time from the start of the deicing cycle or when the set conditions are satisfied by detecting the intake gas temperature. When the pump 3 is started, the ice making water enters the water sprinkling pipe 5 from the ice making water tank 1 via the pipe, and is sprinkled from the water sprinkling hole onto the surface of the ice making plate composed of the evaporator 15 to flow down. The portion that has not been recovered enters the ice making water tank 1 via a path such as a water collecting gutter and circulates. At the same time, in the refrigeration circuit, the hot gas solenoid valve 17 of the deicing circuit is closed, and the refrigerant solenoid valve 1 is closed.
8 is opened, and the refrigerant enters the evaporator 15 from the compressor 11 via the condenser 12, the heat exchanger 13, and the expansion valve 14, cools the ice making plate, and cools the heat exchanger, the accumulator 16, and the compressor 1.
Cycle with 1. Thus, ice is made and stored while repeating the deicing cycle and the ice making cycle.

On the other hand, during the ice making cycle, a temperature detector for detecting the temperature of the ice making water near the water collecting gutter predicts the occurrence of cotton ice, for example, a change in the temperature between 0 and 1 ° C. when the temperature gradually decreases. Is detected, the solenoid valve 18 for refrigerant is closed based on the detection signal until the temperature detector 20 at the inlet of the evaporator 15 rapidly drops to minus several degrees Celsius. Thus, the supply of the refrigerant is temporarily stopped, and the temperature of the ice making plate cooled by the evaporator 15 is rapidly lowered due to the sudden decrease in the gas pressure of the refrigerant, and the temperature difference between the ice making water and the ice making plate is reduced. And ice nuclei necessary for normal ice growth are generated on the surface of the ice making plate. Therefore, no cotton ice was generated at least in the vicinity of the ice making plate where the cotton ice was most likely to be generated.

[0008]

However, in the apparatus according to the above-mentioned proposed invention, the expansion valve 14 or the solenoid valve 18 for the refrigerant is closed during operation to prevent the generation of cotton ice. In this case, the evaporator 15
The internal pressure decreases, and as the evaporation temperature decreases, the ice nuclei are more likely to be generated. As described above, according to the already-proposed device, the additional control is performed as described above only for the countermeasure for preventing generation of cotton ice,
Therefore, until the solenoid valve 18 and the expansion valve 14 are closed and released, only the refrigerant remaining inside the evaporator 15 is used for cooling, so that the actual cooling capacity is small, and at the same time, the temperature of the evaporator 15 is reduced. It is highly likely that cloudy ice will be formed on the ice making surface due to the rapid fall of the ice. That is, there is a problem that the cooling efficiency for the ice making machine is poor and the quality of the ice is adversely affected.

On the other hand, the present applicant has found that the state (condition) where it is difficult to form ice crystal nuclei is generally when some of the following conditions overlap. That is, (1) the purity of the ice-making water as water is good (the amount of impurities constituting the crystal nuclei is small), (2) the ambient temperature of the ice-making machine is high, the performance of the refrigerator is reduced, and the ice-making water is slowly cooled to 0. ° C, and (3) ice-making water is cooled slowly because the ice-making machine originally has no capacity, which is a condition under which ice crystal nuclei are hardly generated.

The present invention has been made to solve the above problems based on the above findings. When the ice making temperature approaches 0 ° C., the cooling performance is transiently enhanced, that is, To provide an incomplete ice generation prevention device for an ice maker that increases the number of rotations of a compressor of a refrigeration circuit and lowers an evaporation temperature to promote crystallization of ice crystals and prevent generation of cotton ice while progressing ice making. With the goal.

[0011]

The present invention has the following configuration to achieve the above object. That is, an ice making machine according to the first aspect of the present invention is an ice making machine for making ice by passing a refrigerant from a refrigerant compressor provided in a refrigeration circuit to an evaporator. A water temperature detector for detecting the temperature of the ice making water in the path of the ice making water, and cooling performance control means for controlling the rotation speed of the inverter compressor by an output signal from the water temperature detector, When the water temperature detector detects that the temperature reaches 0 ° C. or more and near 0 ° C., the cooling performance control means is controlled to increase the rotation speed of the inverter compressor. The invention according to claim 2 relates to the ice making machine according to claim 1, wherein the cooling performance control means has a timer function unit, and the timer function unit holds the water temperature detector at 0 ° C. When counting that a predetermined time has elapsed, the time for controlling to increase the cooling performance is released. The invention according to claim 3 relates to the ice making machine according to claim 1 or 2, wherein the cooling performance control means has a timer function unit, and the timer function unit detects a temperature of the evaporator. When the temperature of the temperature detector becomes equal to or lower than a predetermined value, the time for controlling to increase the cooling performance is released.
The invention according to a fourth aspect relates to the ice making machine according to any one of the first to third aspects, wherein the cooling performance increasing means is configured to perform the cooling performance when the water temperature detector detects a state of 0 ° C. or less. It is characterized by having a learning control function in which the setting is changed so as to increase the rate of increase.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to an embodiment shown in FIGS. FIG. 1 is a system configuration diagram of a water circulation type ice making machine according to an embodiment, FIG. 2 is a characteristic diagram showing a relationship between time and temperature in an ice making cycle, (a) is a normal ice making cycle diagram, (b) FIG. 2 is an ice making cycle diagram when cotton ice is generated, and FIG. 2C is an ice making cycle diagram in the present embodiment. The ice making machine according to the present embodiment is configured such that the compressor is an inverter-type compressor 21 which can control the rotation speed of the compressor 21 to increase or decrease. The difference is that the output signal from the evaporator temperature detector 20 for detecting the temperature of the evaporator 8 and the evaporator is input to the cooling performance control means 22 for controlling the rotation speed of the inverter compressor 21. It is. Therefore, in the following description, the same reference numerals are used for the same members or equivalent members as those described in the conventional device, the description thereof will be omitted, and different configurations will be described.

The cooling performance control means 22 includes a water temperature discrimination section 23 to which an output signal from the ice making water temperature detection section 8 is input, a rotation speed increase output section 24, a timer function section 25, a time release output section 26, an evaporator temperature. It has a classifier 27, a learning control function unit 28, and an increase rate output unit 29. Upon receiving the detection signal from the ice making water temperature detector 8, the water temperature discriminating unit 23 determines whether the temperature is 0 ° C. or more,
When a state close to 0 ° C. is determined (experience value is about 2 ° C.), the rotation speed of the inverter compressor 21 is increased by the output signal from the rotation speed increase output unit 24 to increase the cooling performance. . Then, since the temperature of the evaporator 15 decreases, the temperature difference between the water and the heat exchange surface of the evaporator 15 increases, which leads to an increase in the amount of heat transfer. This facilitates generation of crystal nuclei. Further, when the water temperature determination unit 23 determines that the cooling performance needs to be increased, the timer function unit 2
5. The cooling performance increase time is controlled by the time release output unit 26 and the rotational speed increase output unit 24 to be as short as possible within a required range.

When it is detected that there is no generation of cotton ice and the ice maker freezes, the rotation speed of the inverter compressor 21 is returned to the normal rotation. The detection is performed as follows. That is, the water temperature determination unit 23 determines that the temperature of the ice making water is 0 ° C., and the timer function unit 25 counts and detects that the state of maintaining the 0 ° C. for a certain period of time is continued. The detection signal is output to the time release output unit 26,
In response to the time release signal, the rotation speed increase output unit 24 outputs a command signal so that the rotation speed of the inverter compressor 21 returns to the normal rotation.

As another mode, when the evaporator temperature discriminating section 27 judges that the temperature of the evaporator is below a certain value based on the temperature detected by the temperature detector 20, it passes through the time release output section 26. Then, a release signal for returning the rotation speed of the inverter compressor 21 to the normal rotation speed is output to the rotation speed increase output unit 24.

The time required to increase the cooling performance is released by counting the condition that the temperature of the ice making water is maintained at 0 ° C. for a certain period of time and the temperature of the evaporator 15 to reach a certain temperature or lower. The condition may be canceled by an AND condition that satisfies both conditions, or may be canceled by an OR condition that satisfies one of the conditions.

Further, when the water temperature determining section 23 determines that the ice making water temperature is lower than 0 ° C., it indicates that supercooling (cotton ice) has occurred. At the next ice making cycle, a signal for increasing the rotational speed increase rate of the inverter compressor 21 is output to 29, and such a signal is input to the rotational speed increase output section 24 to increase the rotational speed increase rate of the compressor 15. Feedback.

As described above, according to the present embodiment, when the ice making cycle is in a normal state, the ice making cycle is performed as shown in the graph of FIG. 2 (a), and as shown in FIG. When ice is generated, the learning control function unit 28 provided in the cooling performance control unit 22 changes the setting so that the cooling performance increase rate increases, and the ice making water detector 8 reaches 0 ° C. or more and near 0 ° C. Is detected, the rotation speed of the inverter compressor 21 is increased by the cooling performance control means 22, and as shown in FIG. 2C, there is an effect of preventing the generation of cotton ice while making the ice making progress.

Although the embodiment of the present invention has been described in detail above, the specific configuration is not limited to this embodiment, and there are design changes and the like within a range not departing from the gist of the present invention. Are also included in the present invention. For example, in the above-described embodiment, a water circulation type ice maker has been described. However, the present invention is applicable to any type of ice maker such as a water storage type ice maker.

[0020]

The present invention relates to an ice making machine for making ice by passing a refrigerant from a refrigerant compressor provided in a refrigeration circuit through an evaporator, wherein the refrigerant compressor is formed by a compressor having a variable rotation speed. A water temperature detector for detecting the temperature of the ice making water is provided in the water path, and cooling performance control means for controlling the rotation speed of the compressor based on an output signal from the water temperature detector is provided. When detecting that the temperature has reached about 0 ° C., the cooling performance control means controls the rotation speed of the compressor to increase.
For this reason, when the ice making water temperature approaches 0 ° C., the cooling performance is transiently increased by the cooling performance control means, the nucleation of ice is promoted, and the cotton ice is produced without deterioration of the ice quality. Generation can be prevented before it occurs. Further, unlike the above-mentioned proposed invention, the additional performance is performed only at the expense of cotton ice while sacrificing performance and function, and the generation of cotton ice can be prevented while ice making is being performed. However, since it is easy to control the temperature too low, cloudy ice is not generated and the ice making capacity per hour is improved. As described above, the effect that the high-quality ice can be efficiently produced only by increasing the capacity near the ice making temperature of 0 ° C., that is, by applying the load for a relatively short time to the refrigeration circuit is obtained. Further, since the cooling performance control means has the learning control function part, once the user experiences cotton ice, a learning function for increasing the cooling performance increase rate in the next time can be exhibited, and the effect of improving the ice making ability can be obtained.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a water circulation type ice making machine according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a relationship between time and temperature in an ice making cycle, where (a) is a normal ice making cycle diagram,
(B) is an ice making cycle diagram when cotton ice is generated, (c)
FIG. 4 is an ice making cycle diagram when cooling performance is increased according to the present embodiment.

FIG. 3 is a system configuration diagram of a water circulation type ice making machine according to the proposed invention.

FIG. 4 is a time table in the ice making machine of FIG. 3;

[Explanation of Signs] 8: Ice making water temperature detector, 15: Evaporator (evaporator), 20: Temperature detector, 21: Inverter compressor, 2
2 ... Cooling performance control means, 23 ... Water temperature discriminating unit, 24 ... Rotation speed increase output unit, 25 ... Timer function unit, 27 ... Evaporator temperature discriminating unit, 28 ... Learning function unit.

Claims (4)

[Claims] 1. An ice making machine for making ice by passing a refrigerant from a refrigerant compressor provided in a refrigeration circuit through an evaporator, wherein the refrigerant compressor is formed by a compressor having a variable rotation speed, and is provided in a path of ice making water. A water temperature detector for detecting the temperature of the ice making water is provided, and cooling performance control means for controlling a rotation speed of the compressor based on an output signal from the water temperature detector is provided. An ice making machine characterized in that when it is detected that it has reached the vicinity, the cooling performance control means is controlled to increase the rotation speed of the compressor. 2. The cooling performance control means has a timer function unit, and the timer function unit, when counting that a predetermined time has elapsed after the water temperature detector maintains a state of 0 ° C., 2. The ice making machine according to claim 1, wherein the time for increasing and controlling the cooling performance is canceled. 3. The cooling performance control means has a timer function unit, and the timer function unit is provided when the temperature of an evaporator temperature detector for detecting the temperature of the evaporator becomes lower than a predetermined value.
3. The ice making machine according to claim 1, wherein the time for increasing and controlling the cooling performance is canceled. 4. The cooling performance control means has a learning control function of changing a setting so as to increase an increase rate of the cooling performance when the water temperature detector detects a state of 0 ° C. or less. The ice making machine according to any one of claims 1 to 3.